10th Class Science Sources of Energy Question Bank

done Sources of Energy Total Questions - 147

• question_answer1)
  The phenomenon of ejection of electrons from the surface of metal, when light of a suitable frequency falls on it, is called
  A)
   electrolysis done clear
  B)
   ionization done clear
  C)
   photoelectric effect   done clear
  D)
   none of these done clear
  View Solution play_arrow

• question_answer2)
  The photoelectric effect is described as the ejection of electrons from the surface of a metal when
  A)
   it is heated to a high temperature done clear
  B)
   light of suitable frequency falls on it   done clear
  C)
   electrons of suitable velocity impinge on it done clear
  D)
   it is placed in a strong magnetic field done clear
  View Solution play_arrow

• question_answer3)
  Photoelectric effect was discovered by
  A)
   hertz                      done clear
  B)
          Wallach done clear
  C)
   Lenard                 done clear
  D)
          Millikan done clear
  View Solution play_arrow

• question_answer4)
  A steam engine converts the heat energy of steam into
  A)
   electrical energy              done clear
  B)
   nuclear energy done clear
  C)
   mechanical energy           done clear
  D)
   none of these done clear
  View Solution play_arrow

• question_answer5)
  A motor converts electrical energy into
  A)
   mechanical energy           done clear
  B)
   chemical energy done clear
  C)
   nuclear energy   done clear
  D)
          thermal energy done clear
  View Solution play_arrow

• question_answer6)
  A battery converts chemical energy into
  A)
   mechanical energy         done clear
  B)
   solar energy done clear
  C)
   electrical energy   done clear
  D)
          none of these done clear
  View Solution play_arrow

• question_answer7)
  Ratio of the SI units to CGS units of energy is
  A)
   105                                        done clear
  B)
   106 done clear
  C)
   107                          done clear
  D)
          10.7 done clear
  View Solution play_arrow

• question_answer8)
  Energy possessed by a body due to its motion is
  A)
   kinetic energy      done clear
  B)
          nuclear energy done clear
  C)
   potential energy done clear
  D)
          thermal energy done clear
  View Solution play_arrow

• question_answer9)
  Energy possessed by a body due to its configuration is
  A)
   kinetic energy    done clear
  B)
          nuclear energy done clear
  C)
   potential energy   done clear
  D)
          thermal energy done clear
  View Solution play_arrow

• question_answer10)
  One erg is equal to
  A)
  \[\text{1 g cm }{{\text{s}}^{-\text{2}}}\]         done clear
  B)
          1 Nm done clear
  C)
   \[{{10}^{7}}\,\,J\]             done clear
  D)
          \[{{10}^{-7}}\,\,J\]   done clear
  View Solution play_arrow

• question_answer11)
  The phenomenon of photoelectric effect was explained by                           
  A)
   Wallach         done clear
  B)
          Einstein           done clear
  C)
   Planck                  done clear
  D)
          Bohr done clear
  View Solution play_arrow

• question_answer12)
  A photoelectric cell converts
  A)
   light energy into electrical energy   done clear
  B)
   light energy into sound energy done clear
  C)
   electric energy into light energy done clear
  D)
   light energy into heat energy done clear
  View Solution play_arrow

• question_answer13)
  It is essential to consider light as a stream of photons to explain
  A)
   rectilinear propagation of light done clear
  B)
   photoelectric effect   done clear
  C)
   refraction of light done clear
  D)
   diffraction of light done clear
  View Solution play_arrow

• question_answer14)
  The photoelectric effect can be understood on the basis of
  A)
   wave theory of light only done clear
  B)
   quantum theory of light only   done clear
  C)
   electromagnetic theory of light only done clear
  D)
   none of these done clear
  View Solution play_arrow

• question_answer15)
  Which one of the following is different from the others?                                     
  A)
   Joule                     done clear
  B)
                 Kilowatt hour done clear
  C)
   Erg done clear
  D)
   Watt   done clear
  View Solution play_arrow

• question_answer16)
  If the product of muscle and speed equals power, then the muscle stand for
  A)
   force                      done clear
  B)
          power done clear
  C)
   energy                 done clear
  D)
          momentum done clear
  View Solution play_arrow

• question_answer17)
  Which of the following can't be used to make a solar cell?
  A)
   Silicon            done clear
  B)
          Platinum   done clear
  C)
   Gallium          done clear
  D)
          Germanium done clear
  View Solution play_arrow

• question_answer18)
  With the addition of impurities, the resistance of a semi-conductor
  A)
   increases done clear
  B)
   decreases   done clear
  C)
   first decreases then increases done clear
  D)
   first increases then decreases done clear
  View Solution play_arrow

• question_answer19)
  A photon is a/an
  A)
   quantum of light energy   done clear
  B)
   quantum of matter done clear
  C)
   positively charged particle done clear
  D)
   instrument for measuring light intensity done clear
  View Solution play_arrow

• question_answer20)
  A photon of frequency v has an energy
  A)
   \[\frac{h}{v}\]                  done clear
  B)
          \[\frac{v}{h}\] done clear
  C)
   \[v\]                     done clear
  D)
          \[hv\]   done clear
  View Solution play_arrow

• question_answer21)
  Units of Planck's constant in CGS system are:
  A)
   erg per second done clear
  B)
   second per erg done clear
  C)
   erg second   done clear
  D)
   erg per second per second done clear
  View Solution play_arrow

• question_answer22)
  Planck's constant has the dimensions of
  A)
   energy done clear
  B)
   mass done clear
  C)
   frequency done clear
  D)
   angular momentum   done clear
  View Solution play_arrow

• question_answer23)
  Of the following, the biggest unit of energy is
  A)
   Joule                    done clear
  B)
          Kilowatt hour   done clear
  C)
   Erg                         done clear
  D)
          Electron volt done clear
  View Solution play_arrow

• question_answer24)
  Of the following converts light energy into electrical energy?
  A)
   motor                  done clear
  B)
   battery done clear
  C)
   solar cell           done clear
  D)
          None of these done clear
  View Solution play_arrow

• question_answer25)
  If speed of a motor car becomes six times, then the kinetic energy becomes
  A)
   6 times          done clear
  B)
          36 times   done clear
  C)
   12 times         done clear
  D)
          24 times done clear
  View Solution play_arrow

• question_answer26)
  Spring of the winding knob of a watch has
  A)
   mechanical energy done clear
  B)
   only kinetic energy done clear
  C)
   only potential energy   done clear
  D)
   kinetic or potential energy done clear
  View Solution play_arrow

• question_answer27)
  A body is moved through a distance of 5 m in the following different ways. Maximum work is done when the body is
  A)
   pushed over an inclined plane done clear
  B)
   raised vertically upwards   done clear
  C)
   pushed over smooth rollers done clear
  D)
   pushed on a plane horizontal surface done clear
  View Solution play_arrow

• question_answer28)
  Rest mass of a photon is
  A)
   \[\frac{h\upsilon }{{{c}^{2}}}\]                                  done clear
  B)
   \[\frac{h\upsilon }{c}\] done clear
  C)
   \[h\upsilon \]                                   done clear
  D)
   zero   done clear
  View Solution play_arrow

• question_answer29)
  Mass of a moving photon is
  A)
   \[\frac{h\upsilon }{{{c}^{2}}}\]   done clear
  B)
   \[\frac{h\upsilon }{c}\] done clear
  C)
   \[h\upsilon \]                   done clear
  D)
          zero done clear
  View Solution play_arrow

• question_answer30)
  A photon of frequency v has a momentum associated with it. If c is the velocity of light, then momentum is
  A)
   \[\frac{hv}{{{c}^{2}}}\]                                 done clear
  B)
   \[\frac{hv}{c}\]   done clear
  C)
   \[\frac{v}{c}\]                   done clear
  D)
          \[h\,v\,c\] done clear
  View Solution play_arrow

• question_answer31)
  The momentum of a photon having energy E is
  A)
   \[\frac{E}{c}\]                                     done clear
  B)
   \[\frac{E}{{{c}^{2}}}\] done clear
  C)
   \[\frac{E}{h}\]                  done clear
  D)
          zero done clear
  View Solution play_arrow

• question_answer32)
  The work function of a metal is W and the frequency of incident light is d. There is no emission of photoelectrons when
  A)
   \[v<\frac{W}{h}\]             done clear
  B)
          \[v=\frac{W}{h}\] done clear
  C)
   \[v>\frac{W}{h}\]           done clear
  D)
          \[v\ge \frac{W}{h}\] done clear
  View Solution play_arrow

• question_answer33)
  In the above problem, minimum work is done when the body is
  A)
   pushed over an inclined plane done clear
  B)
   raised vertically upwards done clear
  C)
   pushed over smooth rollers   done clear
  D)
   pushed on a plane horizontal surface done clear
  View Solution play_arrow

• question_answer34)
  A truck and a car are moving on a smooth, level road such that the kinetic energy associated with them is same. Brakes are applied simultaneously in both of them such that equal retarding forces are produced in them. Which one will cover a greater distance before it stops?
  A)
   Car done clear
  B)
   Truck done clear
  C)
   Both will cover the same distance   done clear
  D)
   Nothing can be decided done clear
  View Solution play_arrow

• question_answer35)
  The unit kg \[{{m}^{2}}{{s}^{-2}}\] is associated with
  A)
   work done clear
  B)
   kinetic energy done clear
  C)
   potential energy done clear
  D)
   All of these   done clear
  View Solution play_arrow

• question_answer36)
  Work function is the energy required to
  A)
   producer-rays done clear
  B)
   excite an atom done clear
  C)
   explore an atom done clear
  D)
   eject an electron just out of the surface   done clear
  View Solution play_arrow

• question_answer37)
  Photoelectric effect can be explained only by assuming that light
  A)
   is a form of transverse waves done clear
  B)
   is a form of longitudinal waves done clear
  C)
   can be polarized done clear
  D)
   consists of quanta   done clear
  View Solution play_arrow

• question_answer38)
  In photoelectric effect, the photo current
  A)
   increases with increase of frequency of incident photon done clear
  B)
   decreases with increase of frequency of incident photon done clear
  C)
   does not depend on the frequency of photon but depends only on the intensity of incident light   done clear
  D)
   depends both on intensity and frequency of the incident photon done clear
  View Solution play_arrow

• question_answer39)
  Kinetic energy of a body is increased most by doubling its
  A)
   mass                                     done clear
  B)
   density done clear
  C)
   weight                 done clear
  D)
          speed   done clear
  View Solution play_arrow

• question_answer40)
  A body is dropped from a certain height to the ground. When it is halfway down, then it possesses
  A)
   only kinetic energy done clear
  B)
   only potential energy done clear
  C)
   both kinetic energy and potential energy   done clear
  D)
   neither kinetic energy nor potential energy done clear
  View Solution play_arrow

• question_answer41)
  Usha lifts a doll from the floor and places it on a table. If the weight of the doll is known, what else does one need to know in order to calculate the work Asha has done on the doll?
  A)
   Time required done clear
  B)
   Height of the table   done clear
  C)
   Mass of the doll done clear
  D)
   Cost of the doll done clear
  View Solution play_arrow

• question_answer42)
  A source of light is placed at a distance 1 m from a photocell and cut off potential is found to be \[{{V}_{0}}\] If the distance is doubled, then cut-off potential will be                                  
  A)
   \[\text{2}{{\text{V}}_{0}}\]                        done clear
  B)
         \[{{\text{V}}_{0}}/\text{2}\]           done clear
  C)
   \[{{\text{V}}_{0}}\]                          done clear
  D)
          \[{{\text{V}}_{0}}/\text{2}\]           done clear
  View Solution play_arrow

• question_answer43)
  Of the following, the fuel different from other is
  A)
   charcoal          done clear
  B)
          lignite          done clear
  C)
   coke                     done clear
  D)
          alcohol            done clear
  View Solution play_arrow

• question_answer44)
  In photoelectric effect, the number photoelectrons emitted is proportional to
  A)
   intensity of incident beam       done clear
  B)
   frequency of incident beam done clear
  C)
   velocity of incident beam               done clear
  D)
   work function of photo cathode         done clear
  View Solution play_arrow

• question_answer45)
  The photoelectric threshold of a certain metal is \[\text{3}000\,\overset{\text{o}}{\mathop{\text{A}}}\,\] . If the radiation of\[\text{2}000\,\overset{\text{o}}{\mathop{\text{A}}}\,\] is incident on the metal, then                           
  A)
   electrons will be emitted         done clear
  B)
   positrons will be emitted                done clear
  C)
   protons will be emitted                  done clear
  D)
   electrons will not be emitted             done clear
  View Solution play_arrow

• question_answer46)
  Which of the following statements is correct?
  A)
   current in a photocell increases with increasing frequency of light            done clear
  B)
   photocurrent is proportional to applied voltage                               done clear
  C)
   photocurrent increases with increasing intensity of light   done clear
  D)
   stopping potential increases with increasing intensity of incident light                 done clear
  View Solution play_arrow

• question_answer47)
  If two bodies of equal weights are kept at heights h and 1.5 h respectively, then the ratio of their potential energies is         
  A)
   3 : 2                                       done clear
  B)
   1 : 1              done clear
  C)
   2 : 3                         done clear
  D)
          3 : 4 done clear
  View Solution play_arrow

• question_answer48)
  The acceleration due to gravity on the moon is One - sixth that on the earth. If a high jumper can jump 2 m on earth, then what distance can he jump on the moon?
  A)
   2m                                         done clear
  B)
   12m   done clear
  C)
   6m                         done clear
  D)
          8m                    done clear
  View Solution play_arrow

• question_answer49)
  Solar energy can be used to produce          
  A)
   electrical energy              done clear
  B)
   mechanical energy done clear
  C)
   heat energy      done clear
  D)
          All of these   done clear
  View Solution play_arrow

• question_answer50)
  Which of the following devices transforms light energy into chemical energy?
  A)
   Car dynamo      done clear
  B)
   Electric motor done clear
  C)
   Electric fan       done clear
  D)
   None of these   done clear
  View Solution play_arrow

• question_answer51)
  If momentum of a body increases by 20%, then the percentage increase in its kinetic energy is
  A)
   36                                          done clear
  B)
   44   done clear
  C)
   52                          done clear
  D)
          60 done clear
  View Solution play_arrow

• question_answer52)
  Energy of the electric current is
  A)
   thermal               done clear
  B)
   nuclear done clear
  C)
   electrical           done clear
  D)
          chemical done clear
  View Solution play_arrow

• question_answer53)
  Variation of photoelectric current given by the photocell with the intensity of light is given by a graph, which is
  A)
   a parabola done clear
  B)
   a straight line with positive slope with intercept on current axis   done clear
  C)
   a straight line with positive slope with intercept on current axis done clear
  D)
   a straight line with negative slope done clear
  View Solution play_arrow

• question_answer54)
  Energy of a photon of light of wavelength 450 Nm is
  A)
  \[\text{4}.\text{4 }\times \text{ 1}{{0}^{-\text{19}}}J\]                    done clear
  B)
   \[\text{2}.\text{5 }\times \text{ 1}{{0}^{-\text{19}}}\text{ J}\] done clear
  C)
  \[\text{1}.\text{25 }\times \text{ 1}{{0}^{-\text{17}}}\text{ J}\]     done clear
  D)
          \[\text{2}.\text{5 }\times \text{ 1}{{0}^{-\text{17}}}\text{ J}\] done clear
  View Solution play_arrow

• question_answer55)
  Frequency of a photon having energy \[66\,\,\,eV\] is
  A)
  \[\text{8 }\times \text{ 1}{{0}^{-\text{15}}}\text{ Hz}\]                  done clear
  B)
   \[\text{12 }\times \text{ 1}{{0}^{-\text{15}}}\text{ Hz}\] done clear
  C)
  \[\text{16 }\times \text{ 1}{{0}^{\text{15}}}\text{ Hz}\]        done clear
  D)
          None of these done clear
  View Solution play_arrow

• question_answer56)
  If momentum of a photon of an electromagnetic radiation is\[\text{3}.\text{3 }\times \text{ 1}{{0}^{-\text{29}}}\text{ kg m}/\text{sec}\], then frequency of associated wave is
  A)
  \[\text{3}.0\times \text{1}{{0}^{3}}\text{ Hz}\]                  done clear
  B)
          \[6.0\times \text{l}{{0}^{\text{3}}}\text{Hz}\] done clear
  C)
  \[\text{7}.\text{5 }\times \text{ 1}{{0}^{\text{5}}}\text{ Hz}\]      done clear
  D)
         \[\text{1}.\text{5 }\times \text{ 1}{{0}^{\text{13}}}\text{ Hz}\]   done clear
  View Solution play_arrow

• question_answer57)
  Energy possessed by the wind is
  A)
   kinetic energy      done clear
  B)
          potential energy done clear
  C)
   thermal energy   done clear
  D)
          sound energy done clear
  View Solution play_arrow

• question_answer58)
  Hydro-electric power generates
  A)
   electrical energy   done clear
  B)
         nuclear energy done clear
  C)
   thermal energy   done clear
  D)
          None of these done clear
  View Solution play_arrow

• question_answer59)
  he steam engine was invented by
  A)
   James Watt      done clear
  B)
   Joule done clear
  C)
    New common      done clear
  D)
         Newton done clear
  View Solution play_arrow

• question_answer60)
  The fuel used in a steam engine is
  A)
   water                                   done clear
  B)
   carbon dioxide done clear
  C)
   carbon monoxide           done clear
  D)
   none of these   done clear
  View Solution play_arrow

• question_answer61)
  The petrol engine was invented by
  A)
   Nikolaus Otto                     done clear
  B)
   James Watt done clear
  C)
   Rudolph Diesel                 done clear
  D)
   None of these done clear
  View Solution play_arrow

• question_answer62)
  Momentum of a photon having frequency \[\text{1}.\text{5 }\times \text{ 1}{{0}^{\text{13}}}\text{ Hz}\]?
  A)
   \[\text{3}.\text{3 }\times \text{ 1}{{0}^{-\text{29}}}\text{ kg m}/\text{s}\]           done clear
  B)
  \[\text{3}.\text{3 }\times \text{ 1}{{0}^{-\text{34}}}\text{ kg m}/\text{s}\] done clear
  C)
   \[\text{6}.\text{6 }\times \text{ 1}{{0}^{-\text{34}}}\text{ kg m}/\text{s}\]         done clear
  D)
   \[\text{6}.\text{6 }\times \text{ 1}{{0}^{-\text{3}0}}\text{ kg m}/\text{s}\] done clear
  View Solution play_arrow

• question_answer63)
  Einstein's photoelectric equation is
  A)
   \[h\upsilon =\frac{{{W}_{0}}}{2}-m{{\upsilon }^{2}}\] done clear
  B)
          \[h\upsilon ={{W}_{0}}\frac{1}{2}m{{\upsilon }^{2}}\] done clear
  C)
   \[h\upsilon ={{W}_{0}}+\frac{1}{2}m{{\upsilon }^{2}}\]   done clear
  D)
          \[h\upsilon =\frac{1}{2}m{{\upsilon }^{2}}-{{W}_{0}}\] done clear
  View Solution play_arrow

• question_answer64)
  Joule's experiment converts
  A)
   work into heat   done clear
  B)
   work into electricity done clear
  C)
   heat into work done clear
  D)
   electricity into work done clear
  View Solution play_arrow

• question_answer65)
  One watt hour equals
  A)
   3600 J              done clear
  B)
          360 J done clear
  C)
   36 J                        done clear
  D)
          3.6 J done clear
  View Solution play_arrow

• question_answer66)
  Of the following, the fuel having different from others is
  A)
   water gas           done clear
  B)
   coal gas done clear
  C)
   producer gas     done clear
  D)
          coke   done clear
  View Solution play_arrow

• question_answer67)
  Of the following, the fuel different from others is
  A)
   Diesel                   done clear
  B)
          Gasoline done clear
  C)
   Alcohol           done clear
  D)
          Lignite   done clear
  View Solution play_arrow

• question_answer68)
  A solar cell converts heat and light energy into
  A)
   heat energy       done clear
  B)
          sound energy done clear
  C)
   electricity           done clear
  D)
          nuclear energy done clear
  View Solution play_arrow

• question_answer69)
  One mega joule approximately equals
  A)
   240 kcal   done clear
  B)
                          2400 kcal done clear
  C)
   24 kcal                  done clear
  D)
          2.4 kcal done clear
  View Solution play_arrow

• question_answer70)
  Of the following, the fuel having least calorific value is
  A)
   Petrol                                   done clear
  B)
   Kerosene done clear
  C)
   Diesel                   done clear
  D)
          Coke   done clear
  View Solution play_arrow

• question_answer71)
  The photoelectric work function
  A)
   is different for different metals   done clear
  B)
   is same for all metals done clear
  C)
   depends upon frequency of incident light done clear
  D)
   depends upon intensity of incident light done clear
  View Solution play_arrow

• question_answer72)
  The current in a photoelectric tube
  A)
   decreases with increase in frequency of the incident photon done clear
  B)
   increases with increase in frequency of the incident photon done clear
  C)
   decreases with increases in intensity of illumination done clear
  D)
   increases with increase in intensity of illumination   done clear
  View Solution play_arrow

• question_answer73)
  A metallic surface ejects photoelectrons when hit by green light but none when hit by yellow light. Will the electrons be ejected if the same surface is hit by red light?
  A)
   yes done clear
  B)
   yes, if the red beam is sufficiently intense   done clear
  C)
   can?t say done clear
  D)
   none of these done clear
  View Solution play_arrow

• question_answer74)
  Heat flows as a result of difference in
  A)
   masses                done clear
  B)
   weights done clear
  C)
   temperatures       done clear
  D)
          none of these done clear
  View Solution play_arrow

• question_answer75)
  Temperature of water at the bottom of a waterfall is higher than that of the water at the top, because
  A)
   falling water absorbs heat from the sun done clear
  B)
   kinetic energy of the falling water is converted into heat   done clear
  C)
   water at the bottom has greater potential energy done clear
  D)
   the rocks on the river bed give out heat done clear
  View Solution play_arrow

• question_answer76)
  Work done can be converted from joules to calories by
  A)
   dividing by \[J\]       done clear
  B)
         subtracting \[J\] done clear
  C)
   multiplying by \[J\]         done clear
  D)
   adding \[J\] where,\[J\]= mechanical equivalent of heat. done clear
  View Solution play_arrow

• question_answer77)
  A car engine is an example of
  A)
   internal combustion engine   done clear
  B)
   external combustion engine done clear
  C)
   neither internal nor external combustion engine done clear
  D)
   both internal and external combustion engines done clear
  View Solution play_arrow

• question_answer78)
  Cathode rays are
  A)
   a stream of electrons   done clear
  B)
   a stream of positive ions done clear
  C)
   a stream of uncharged particles done clear
  D)
   same as canal rays done clear
  View Solution play_arrow

• question_answer79)
  If cathode rays enter a magnetic field making an oblique angle with lines of induction, then their path in the magnetic field is
  A)
   A straight line                   done clear
  B)
   Helix   done clear
  C)
   A circle           done clear
  D)
          Parabola done clear
  View Solution play_arrow

• question_answer80)
  The specific charge for cathode rays is
  A)
   constant   done clear
  B)
   variable done clear
  C)
   dependent upon the material of the cathode done clear
  D)
   dependent upon the nature of gas in the discharge tube done clear
  View Solution play_arrow

• question_answer81)
  The practical unit for the measurement of electric power is
  A)
   watt                        done clear
  B)
          kilowatt done clear
  C)
   kilowatt hour     done clear
  D)
          horse power done clear
  View Solution play_arrow

• question_answer82)
  Wood is a
  A)
   primary fuel        done clear
  B)
          liquid fuel done clear
  C)
   processed fuel    done clear
  D)
          secondary fuel done clear
  View Solution play_arrow

• question_answer83)
  An example of secondary fuel is
  A)
   coal                                       done clear
  B)
   water gas   done clear
  C)
   natural gas       done clear
  D)
          petroleum done clear
  View Solution play_arrow

• question_answer84)
  Which of the following is an example of fossil fuel?
  A)
   Coal gas          done clear
  B)
          Coke done clear
  C)
   Natural gas        done clear
  D)
          Producer gas done clear
  View Solution play_arrow

• question_answer85)
  Most of the fuels are
  A)
   carbon compounds with sulphur         done clear
  B)
   nitrogen compounds with carbon   done clear
  C)
   carbon compounds with hydrogen done clear
  D)
   None of these done clear
  View Solution play_arrow

• question_answer86)
  Cathode rays rain K. E. when they are accelerated by an electric field. If cathode rays are subjected to the action of magnetic field, then their
  A)
   energy increases done clear
  B)
   momentum increases done clear
  C)
   potential energy increases done clear
  D)
   energy and momentum remain unaffected   done clear
  View Solution play_arrow

• question_answer87)
  The force experienced by an electron with constant velocity parallel to the direction o1 uniform magnetic field B is
  A)
   \[eVB\]               done clear
  B)
          \[\frac{eV}{B}\] done clear
  C)
    \[eB\]                        done clear
  D)
            Zero   done clear
  View Solution play_arrow

• question_answer88)
  Destructive distillation of coal leads to the formation of
  A)
   wood                   done clear
  B)
   kerosene done clear
  C)
   ammonia Cal liquor          done clear
  D)
   charcoal done clear
  View Solution play_arrow

• question_answer89)
  When steam is passed over hot coke, it produces
  A)
   producer gas                     done clear
  B)
   water gas   done clear
  C)
   laughing gas     done clear
  D)
   coal gas done clear
  View Solution play_arrow

• question_answer90)
  Producer gas is a mixture of
  A)
   carbon monoxide and nitrogen gas   done clear
  B)
   carbon monoxide and hydrogen gas done clear
  C)
   carbon monoxide and water vapour done clear
  D)
   carbon monoxide and nitrous oxide done clear
  View Solution play_arrow

• question_answer91)
  The fractional distillation of coaltar yields
  A)
   carbon disulphide done clear
  B)
   kerosene oil done clear
  C)
   carbon tetrachloride done clear
  D)
   benzene   done clear
  View Solution play_arrow

• question_answer92)
  Which of the following is not obtained on fractional distillation of petroleum?
  A)
   Paraffin wax      done clear
  B)
          Asphalt done clear
  C)
   Coal gas                 done clear
  D)
   Petroleum gas done clear
  View Solution play_arrow

• question_answer93)
  Cathode ray oscillo graph is used for
  A)
   taking X-ray photographs done clear
  B)
   showing pictures done clear
  C)
   demonstrating electrical pulses   done clear
  D)
   producing elementary particles done clear
  View Solution play_arrow

• question_answer94)
  Number of thermo electrons emitted per second from the cathode does not depend upon
  A)
   specific heat capacity of the cathode   done clear
  B)
   temperature of the cathode done clear
  C)
   surface area of the cathode done clear
  D)
   work function of the metal cathode done clear
  View Solution play_arrow

• question_answer95)
  Which of the following is formed under the earth by the decomposition of plant matter by anaerobic bacteria lying under water?
  A)
   Coal gas done clear
  B)
   Petroleum gas done clear
  C)
   Natural gas   done clear
  D)
   Producer gas done clear
  View Solution play_arrow

• question_answer96)
  Which of the following is not used as a rocket fuel?
  A)
   Synthetic rubber             done clear
  B)
   Liquid hydrogen done clear
  C)
   Paraffin               done clear
  D)
   Liquid nitrogen   done clear
  View Solution play_arrow

• question_answer97)
  Which of the following compound has a least heating value?
  A)
   Alcohol           done clear
  B)
          Biogas done clear
  C)
   Wood               done clear
  D)
          Coal done clear
  View Solution play_arrow

• question_answer98)
  In the reaction, \[2C{{H}_{4}}+4{{O}_{2}}\to 2{{O}_{2}}+4{{H}_{2}}O+\] \[1780\,kJ\], the calorific value of methane is about
  A)
   55 kJ/g             done clear
  B)
          110 kJ/g done clear
  C)
   110 J/g           done clear
  D)
          55 J/g done clear
  View Solution play_arrow

• question_answer99)
  When a cathode ray tube is operated at 2912 volt, then velocity of electrons is \[\text{3}.\text{2 }\times \text{ 1}{{0}^{7}}\] m/s. The velocity of cathode ray, if the tube is operated at 5824 volt, will be
  A)
  \[\text{4}.\text{48 }\times \text{ 1}{{0}^{\text{6}}}\text{ m}/\text{sec}\] done clear
  B)
         \[\text{4}.\text{48 }\times \text{ 1}{{0}^{\text{7}}}\text{ m}/\text{sec}\]   done clear
  C)
  \[\text{8}.\text{44 }\times \text{ 1}{{0}^{\text{6}}}\text{ m}/\text{sec}\] done clear
  D)
          \[\text{8}.\text{88 }\times \text{ 1}{{0}^{\text{7}}}\text{ m}/\text{sec}\] done clear
  View Solution play_arrow

• question_answer100)
  In a cathode ray oscillograph, the focusing of beam on the screen is achieved by
  A)
   convex lenses     done clear
  B)
          magnetic field done clear
  C)
   electric potential   done clear
  D)
          All of these done clear
  View Solution play_arrow

• question_answer101)
   An electric field of intensity \[6\times 104volts/m\] is applied perpendicular to the direction of motion of the electron. A magnetic field of intensity \[\text{8 }\times \text{ 1}{{0}^{-\text{2}}}\text{ wb}/{{\text{m}}^{\text{2}}}\]is applied perpendicular to both the electric field and direction of motion of the electron. What is the velocity of the electron if it passes un deflected?
  A)
   \[\text{7}.\text{5 }\times \text{ 1}{{0}^{\text{5}}}\text{ m}/\text{s}\]   done clear
  B)
   \[\text{7}.\text{5 }\times \text{ 1}{{0}^{-\text{5}}}\text{ m}/\text{s}\] done clear
  C)
   \[\text{6}\times \text{ 1}{{0}^{\text{4}}}\times \text{8 }\times \text{ l}{{\text{0}}^{-\text{2}}}\text{ m}/\text{s}\] done clear
  D)
   It is never possible done clear
  View Solution play_arrow

• question_answer102)
  Kerosene burns more rapidly than coke because
  A)
   it has got more oxygen in it than coke done clear
  B)
   it is a liquid hydrocarbon done clear
  C)
   it has a low ignition temperature   done clear
  D)
   None of these done clear
  View Solution play_arrow

• question_answer103)
  Which of the following is not an example of spontaneous combustion?
  A)
   Burning of liquefied petroleum gas   done clear
  B)
   Fire caused in coal mines done clear
  C)
   Dry white phosphorous liberates white fumes on exposure to air done clear
  D)
   All of these done clear
  View Solution play_arrow

• question_answer104)
  Of the following, flames produced by a candle is
  A)
   Blue flame done clear
  B)
   Non-luminous flame done clear
  C)
   Light giving flame done clear
  D)
   yellow luminous flame   done clear
  View Solution play_arrow

• question_answer105)
  Unburnt carbon particles are present in the
  A)
   blue zone           done clear
  B)
   dark inner zone done clear
  C)
   luminous zone                   done clear
  D)
   non-luminous zone done clear
  View Solution play_arrow

• question_answer106)
  An electron is moving with velocity 107 m/s on a circular path of radius 0.57 cm in a magnetic field of\[\text{1}{{0}^{-\text{2}}}\text{ wb}/{{\text{m}}^{\text{2}}}\]. The value of elm for electron will  be
  A)
  \[\text{1}\text{.76 }\times \text{ 1}{{0}^{\text{9}}}\text{ C}/\text{kg}\]                done clear
  B)
   \[\text{1}\text{.76 }\times \text{ 1}{{0}^{\text{1}0}}\text{ C}/\text{kg}\] done clear
  C)
  \[\text{1}\text{.76 }\times \text{ 1}{{0}^{\text{11}}}\text{ C}/\text{kg}\]                done clear
  D)
   \[\text{1}\text{.76 }\times \text{ 1}{{0}^{\text{12}}}\text{ C}/\text{kg}\] done clear
  View Solution play_arrow

• question_answer107)
  Photoelectric effect can be explained only by assuming that
  A)
   light is a form of transverse waves done clear
  B)
   light is a form of longitudinal waves done clear
  C)
   light can be polarized done clear
  D)
   light consists of quanta   done clear
  View Solution play_arrow

• question_answer108)
  Light of a particular frequency o is incident on a metal surface. When the intensity of incident radiation is increased, then photoelectric current
  A)
   decreases done clear
  B)
   increases   done clear
  C)
   remains unchanged done clear
  D)
   sometimes increases and sometimes decreases done clear
  View Solution play_arrow

• question_answer109)
  Of the following a supporter of combustion is
  A)
   Cooking gas      done clear
  B)
          Nitrogen gas done clear
  C)
   Oxygen gas        done clear
  D)
          Producer gas done clear
  View Solution play_arrow

• question_answer110)
  Biogas is a mixture of
  A)
  \[CO+{{H}_{2}}+C{{H}_{4}}\] done clear
  B)
  \[C{{O}_{2}}+C{{H}_{4}}+{{H}_{2}}+{{H}_{2}}S\]   done clear
  C)
   \[CO+{{H}_{2}}\]             done clear
  D)
   \[C{{O}_{2}}+{{N}_{2}}\] done clear
  View Solution play_arrow

• question_answer111)
  Of the following, non-renewable source of energy is
  A)
   Coal                                        done clear
  B)
   Gobar gas done clear
  C)
   Solar energy     done clear
  D)
   Tidal energy done clear
  View Solution play_arrow

• question_answer112)
  Of the following, renewable source of energy is
  A)
   Wood                     done clear
  B)
          Petroleum done clear
  C)
   Natural gas      done clear
  D)
          Uranium done clear
  View Solution play_arrow

• question_answer113)
  The photoelectric effect is based on the conservation of
  A)
   energy                                   done clear
  B)
   momentum done clear
  C)
   mass                                     done clear
  D)
   angular momentum done clear
  View Solution play_arrow

• question_answer114)
  Photoelectric effect is described as the ejection of electrons from the surface of metal when
  A)
   it is heated to high temperature done clear
  B)
   light of suitable wavelength falls on it   done clear
  C)
   electrons of a suitable velocity impinge or done clear
  D)
   it is placed in a strong magnetic field done clear
  View Solution play_arrow

• question_answer115)
  The idea of quantum nature of light has emerged  in an attempt to explain
  A)
   the thermal radiations of a black body   done clear
  B)
   the interference of light done clear
  C)
   radioactivity done clear
  D)
   thermionic emission done clear
  View Solution play_arrow

• question_answer116)
  The sources of energy which are being produced continuously in nature and are inexhaustible, are  called
  A)
   conventional sources done clear
  B)
   non-renewable sources done clear
  C)
   non-conventional sources   done clear
  D)
   None of these done clear
  View Solution play_arrow

• question_answer117)
  The source of energy which is different from others is
  A)
   wood                                   done clear
  B)
   ailing water done clear
  C)
   wind                                     done clear
  D)
   petroleum   done clear
  View Solution play_arrow

• question_answer118)
  The source of energy, which is different from others is
  A)
   gobar gas done clear
  B)
   vegetable refuse done clear
  C)
   plants done clear
  D)
   crude oil   done clear
  View Solution play_arrow

• question_answer119)
  The source of energy which is different from others is
  A)
   natural gas         done clear
  B)
   petroleum done clear
  C)
   uranium              done clear
  D)
   wood   done clear
  View Solution play_arrow

• question_answer120)
  The source of energy which is different from others is
  A)
   lignite                   done clear
  B)
          natural gas done clear
  C)
   sun                          done clear
  D)
          coal done clear
  View Solution play_arrow

• question_answer121)
  Mass of the photon at rest is
  A)
  \[\text{1}.\text{67 }\times \text{ 1}{{0}^{-\text{35}}}\text{ kg}\]              done clear
  B)
   one a. m. u. done clear
  C)
  \[\text{9 }\times \text{ 1}{{0}^{-\text{31}}}\text{ kg}\]                  done clear
  D)
   zero   done clear
  View Solution play_arrow

• question_answer122)
  If the work function of the metal is \[\phi \] and the frequency of incident light is \[\upsilon \] there is no emission of photoelectrons when
  A)
   \[\upsilon =\frac{\phi }{h}\]       done clear
  B)
          \[\upsilon >\frac{\phi }{h}\] done clear
  C)
   \[\upsilon <\frac{\phi }{h}\]         done clear
  D)
          \[\upsilon >=\frac{\phi }{h}\] done clear
  View Solution play_arrow

• question_answer123)
  Which one of the following statement about 'photon is correct?
  A)
   photon's rest mass is zero done clear
  B)
   Momentum of photon is \[\frac{h\upsilon }{c}\] done clear
  C)
   Photon's energy is \[h\upsilon \] done clear
  D)
   All of these   done clear
  View Solution play_arrow

• question_answer124)
  If work function of a photoelectric material is \[3.3\,eV\], then threshold frequency will be
  A)
   \[8\times {{10}^{14}}Hz\]   done clear
  B)
   \[8\times {{10}^{56}}Hz\] done clear
  C)
    \[\text{8 }\times \text{ 1}{{0}^{\text{1}0}}\text{ Hz}\] done clear
  D)
   \[\text{8 }\times \text{ 1}{{0}^{\text{11}}}\text{ Hz}\] done clear
  View Solution play_arrow

• question_answer125)
  Difference in the concentration of salts in water of two different seas is called
  A)
   ocean current done clear
  B)
   nuclear fission done clear
  C)
   oceanography done clear
  D)
   salinity gradient   done clear
  View Solution play_arrow

• question_answer126)
  Energy available due to the difference in the temperature of water at the surface of the ocean and at deeper levels is called
  A)
   tidal energy done clear
  B)
   wind energy done clear
  C)
   solar energy done clear
  D)
   None of these   done clear
  View Solution play_arrow

• question_answer127)
  The vast amount of sea weeds present in oceans may provide an endless source of
  A)
   nuclear energy done clear
  B)
   methane done clear
  C)
   thermal energy ocean done clear
  D)
   None of these   done clear
  View Solution play_arrow

• question_answer128)
  Energy of water is called
  A)
   mechanical energy done clear
  B)
   hydroenergy done clear
  C)
   solar energy done clear
  D)
   None of these   done clear
  View Solution play_arrow

• question_answer129)
  If energy of the photon is 10 eV, the momentum of the photon is
  A)
   \[\text{5}.\text{33 }\times \text{ 1}{{0}^{-\text{25}}}\text{ kg m}/\text{s}\] done clear
  B)
   \[5.33\times {{10}^{-27}}m/s\]   done clear
  C)
   \[5.33\times {{10}^{-29}}Kg\,\,m/s\] done clear
  D)
   \[5.33\times {{10}^{-23}}kg\,m/s\] done clear
  View Solution play_arrow

• question_answer130)
  The threshold wavelength for lithium is 5250\[\overset{\text{o}}{\mathop{\text{A}}}\,\]. For photo emission to take place, the wavelength of the incident light must be
  A)
   more than \[\text{525}0\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  B)
   exactly equal to \[\text{525}0\text{ }\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  C)
   equal to or more than \[\text{525}0\text{ }\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  D)
   equal to or less than \[\text{525}0\text{ }\overset{\text{o}}{\mathop{\text{A}}}\,\]   done clear
  View Solution play_arrow

• question_answer131)
  Relation between energy, E and momentum, p of the photon is given by\[E=hv\,and\,p=\frac{h}{\lambda }\] The velocity of the photon will be
  A)
   \[\frac{E}{p}\]                                    done clear
  B)
   \[Ep\] done clear
  C)
   \[{{\left( \frac{E}{p} \right)}^{2}}\]          done clear
  D)
          \[{{\left( \frac{E}{p} \right)}^{\frac{1}{2}}}\] done clear
  View Solution play_arrow

• question_answer132)
  The generation of electricity from water energy
  A)
   will never get exhausted done clear
  B)
   will not produce any environmental pollution done clear
  C)
   is renewable source of energy done clear
  D)
   All the above are correct   done clear
  View Solution play_arrow

• question_answer133)
  Energy available from the oceans is
  A)
   OTE done clear
  B)
   tidal energy done clear
  C)
   sea-waves energy done clear
  D)
   all of these   done clear
  View Solution play_arrow

• question_answer134)
  Which of the following is not a form of oceanic energy?
  A)
   Energy from biomass done clear
  B)
   Tidal energy done clear
  C)
   Ocean thermal energy done clear
  D)
   Solar energy   done clear
  View Solution play_arrow

• question_answer135)
  At many places in the ocean, the difference in temperatures between the water 'at the surface of ocean' and 'at deeper levels' is up to
  A)
  \[120{}^\circ C\] done clear
  B)
  \[80{}^\circ C\] done clear
  C)
  \[50{}^\circ C\] done clear
  D)
  \[20{}^\circ C\]   done clear
  View Solution play_arrow

• question_answer136)
  The oceans cover almost _______ percent of the surface of earth with water and act as a vast collector of________ energy.
  A)
   71, chemical done clear
  B)
   97, solar done clear
  C)
   71, solar   done clear
  D)
   17, hydroenergy done clear
  View Solution play_arrow

• question_answer137)
  Photoelectric work function of a metal is 1 eV and light of wavelength \[\lambda \] = \[\text{3000 }\overset{\text{o}}{\mathop{\text{A}}}\,\] falls on it. The photoelectrons come out with velocity
  A)
   \[\text{1}{{0}^{\text{2}}}\text{ m}/\text{s}\] done clear
  B)
   \[\text{1}{{0}^{\text{4}}}\text{ m}/\text{s}\] done clear
  C)
   \[\text{1}{{0}^{\text{6}}}\text{ Ws}\]   done clear
  D)
   \[\text{1}{{0}^{\text{8}}}\text{ m}/\text{s}\] done clear
  View Solution play_arrow

• question_answer138)
  Number of photons emitted in 10 hours by 60 W sodium lamp is \[(\lambda =5893\overset{\circ }{\mathop{A}}\,)\]
  A)
   \[\text{6}.\text{4}0\text{ }\times \text{ 1}{{0}^{\text{22}}}\] done clear
  B)
   \[\text{6}.\text{4}0\text{ }\times \text{ 1}{{0}^{\text{24}}}\]   done clear
  C)
   \[\text{4}.\text{6}0\text{ }\times \text{ 1}{{0}^{\text{22}}}\] done clear
  D)
   \[\text{4}.\text{6}0\text{ }\times \text{ 1}{{0}^{\text{24}}}\] done clear
  View Solution play_arrow

• question_answer139)
  If work function of a metal surface is 4.2 eV, then maximum wavelength which can eject electrons from this metal surface is
  A)
  \[\text{3}0\text{79}\overset{\circ }{\mathop{A}}\,\] done clear
  B)
  \[~\text{4116}\overset{\circ }{\mathop{A}}\,\] done clear
  C)
   \[\text{2956}\overset{\circ }{\mathop{A}}\,\]   done clear
  D)
  \[\text{5}0\text{88}\overset{\circ }{\mathop{A}}\,\] done clear
  View Solution play_arrow

• question_answer140)
  The surface of some material is radiated in turn, by waves of \[\lambda =3.5\times {{10}^{-7}}m\]and \[\lambda =5.4\times {{10}^{-7}}m\]respectively. The ratio of the stopping potential in the two cases is 2 : 1. The work function of the metal is
  A)
   \[1.05\,eV\]   done clear
  B)
   \[1.5\,eV\] done clear
  C)
   \[2.05\,eV\] done clear
  D)
   \[2.5\,eV\] done clear
  View Solution play_arrow

• question_answer141)
  At present, the contribution of hydroelectricity to the total power generation in India is
  A)
   a little more than 23%   done clear
  B)
   a little more than 35% done clear
  C)
   a little more than 47% done clear
  D)
   none of these done clear
  View Solution play_arrow

• question_answer142)
  Which of the following is not a high wind-energy region of India?
  A)
   Bay of Bengal done clear
  B)
   Gujarat done clear
  C)
   The Arabian sea Islands done clear
  D)
   Punjab   done clear
  View Solution play_arrow

• question_answer143)
  Wind-energy map gives information about the
  A)
   causes of wind done clear
  B)
   amount of rainfall done clear
  C)
   intensity of earthquake done clear
  D)
   none of these   done clear
  View Solution play_arrow

• question_answer144)
  If ultra-violet radiation of 6.2 eV falls on an aluminium surface (work function 4.2 eV ), then K.E. in joules of the fastest electron emitted is approximately
  A)
   \[\text{3 }\times \text{ 1}{{0}^{-\text{23}}}\] done clear
  B)
   \[\text{3 }\times \text{ 1}{{0}^{-\text{21}}}\] done clear
  C)
   \[\text{3 }\times \text{ 1}{{0}^{-\text{19}}}\]   done clear
  D)
   \[\text{3 }\times \text{ 1}{{0}^{-\text{17}}}\] done clear
  View Solution play_arrow

• question_answer145)
  The work function of a metal is 2.5 eV. If tin radiation of wavelength 4000A falls on it, then energy of emitted photoelectrons will be
  A)
   0.402 eV done clear
  B)
   0.204 eV done clear
  C)
   0.306 eV done clear
  D)
   \[0.\text{6}0\text{3 eV}\]   done clear
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• question_answer146)
  If work function of cesium is 1.8 eV, and light of \[\text{5}000\overset{\circ }{\mathop{A}}\,\] is incident on it, then maximum velocity of emitted electrons is
  A)
   \[\text{5 }\times \text{ 1}{{0}^{\text{3}}}\text{ m}/\text{s}\] done clear
  B)
   \[\text{5 }\times \text{ 1}{{0}^{\text{4}}}\text{ m}/\text{s}\] done clear
  C)
   \[\text{5}.0\text{ }\times \text{ 1}{{0}^{\text{5}}}\text{ m}/\text{s}\]   done clear
  D)
   \[\text{5 }\times \text{ 1}{{0}^{\text{6}}}\text{ m}/\text{s}\] done clear
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• question_answer147)
  Of the following, the fuel having greatest calorific value is
  A)
   Petrol   done clear
  B)
   Kerosene done clear
  C)
   Biogas done clear
  D)
   Coke done clear
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