JEE Main & Advanced Physics Wave Optics / तरंग प्रकाशिकी Question Bank

done EM Waves Total Questions - 67

• question_answer1)
  Which of the following statement is wrong       [NCERT 1976]
  A)
             Infrared photon has more energy than the photon of visible light done clear
  B)
             Photographic plates are sensitive to ultraviolet rays done clear
  C)
             Photographic plates can be made sensitive to infrared rays done clear
  D)
             Infrared rays are invisible but can cast shadows like visible light rays done clear
  View Solution play_arrow

• question_answer2)
  Pick out the longest wavelength from the following types of radiations                                  [CBSE PMT 1990]
  A)
             Blue light                                done clear
  B)
             g-rays done clear
  C)
             X-rays                                      done clear
  D)
             Red light done clear
  View Solution play_arrow

• question_answer3)
  Wave which cannot travel in vacuum is           [MP PMT 1994]
  A)
             X-rays                                      done clear
  B)
             Infrasonic done clear
  C)
             Ultraviolet                              done clear
  D)
             Radiowaves done clear
  View Solution play_arrow

• question_answer4)
  Light is an electromagnetic wave. Its speed in vacuum is given by the expression [CBSE PMT 1993; MP PMT 1994; RPMT 1999; MP PET 2001; Kerala PET 2001; AIIMS 2002]
  A)
             \[\sqrt{{{\mu }_{o}}{{\varepsilon }_{o}}}\]                  done clear
  B)
             \[\sqrt{\frac{{{\mu }_{o}}}{{{\varepsilon }_{o}}}}\] done clear
  C)
             \[\sqrt{\frac{{{\varepsilon }_{o}}}{{{\mu }_{o}}}}\] done clear
  D)
             \[\frac{1}{\sqrt{{{\mu }_{o}}{{\varepsilon }_{o}}}}\] done clear
  View Solution play_arrow

• question_answer5)
  The range of wavelength of the visible light is  [MP PMT 2000; MP PET 2002]
  A)
  \[10\,\,{AA}\]to\[100\,\,{AA}\]                                    done clear
  B)
  \[4,000\,\,{AA}\]to\[8,000\,\,{AA}\] done clear
  C)
  \[8,000\,\,{AA}\]to\[10,000\,\,{AA}\]                        done clear
  D)
  \[10,000\,\,{AA}\]to\[15,000\,\,{AA}\] done clear
  View Solution play_arrow

• question_answer6)
  Which radiation in sunlight, causes heating effect [AFMC 2001]
  A)
             Ultraviolet                              done clear
  B)
             Infrared done clear
  C)
             Visible light                            done clear
  D)
             All of these done clear
  View Solution play_arrow

• question_answer7)
  Which of the following represents an infrared wavelength [CPMT 1975; MP PET/PMT 1988]
  A)
             \[{{10}^{-4}}\] cm               done clear
  B)
             \[{{10}^{-5}}\] cm done clear
  C)
             \[{{10}^{-6}}\]cm                done clear
  D)
             \[{{10}^{-7}}\]cm done clear
  View Solution play_arrow

• question_answer8)
  The wavelength of light visible to eye is of the order of [CPMT 1982, 84]
  A)
             \[{{10}^{-2}}\,\,m\]            done clear
  B)
             \[{{10}^{-10}}\] m done clear
  C)
             1 m                                            done clear
  D)
             \[6\times {{10}^{-7}}\]m done clear
  View Solution play_arrow

• question_answer9)
  The speed of electromagnetic wave in vacuum depends upon the source of radiation [Kerala PMT 2004]
  A)
             Increases as we move from g-rays to radio waves done clear
  B)
             Decreases as we move from g-rays to radio waves done clear
  C)
             Is same for all of them      done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer10)
  Which of the following radiations has the least wavelength [AIEEE 2003]
  A)
             g -rays                                      done clear
  B)
             b-rays done clear
  C)
             a-rays                                      done clear
  D)
             X-rays done clear
  View Solution play_arrow

• question_answer11)
  The maximum distance upto which TV transmission from a TV tower of height h can be received is proportional to [AIIMS 2003]
  A)
             \[{{h}^{1/2}}\]                      done clear
  B)
             h done clear
  C)
             h     done clear
  D)
             \[{{h}^{2}}\] done clear
  View Solution play_arrow

• question_answer12)
  Which of the following are not electromagnetic waves [AIEEE 2002; CBSE PMT 2003]
  A)
             Cosmic rays                           done clear
  B)
             Gamma rays done clear
  C)
             b-rays                                      done clear
  D)
             X-rays done clear
  View Solution play_arrow

• question_answer13)
  Ozone is found in                                                          [DPMT 2002]
  A)
             Stratosphere                        done clear
  B)
             Ionosphere done clear
  C)
             Mesosphere                         done clear
  D)
             Troposphere done clear
  View Solution play_arrow

• question_answer14)
  The electromagnetic waves travel with a velocity [J & K CET 2002]
  A)
             Equal to velocity of sound done clear
  B)
             Equal to velocity of light done clear
  C)
             Less than velocity of light done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer15)
  The ozone layer absorbs                                     [Kerala PET 2002]
  A)
             Infrared radiations             done clear
  B)
             Ultraviolet radiations done clear
  C)
             X-rays                                      done clear
  D)
             g-rays done clear
  View Solution play_arrow

• question_answer16)
  Electromagnetic radiation of highest frequency is [Kerala PMT 2002]
  A)
             Infrared radiations             done clear
  B)
             Visible radiation done clear
  C)
             Radio waves                          done clear
  D)
             g-rays done clear
  View Solution play_arrow

• question_answer17)
  Which of the following shows greenhouse effect [CBSE PMT 2002]
  A)
             Ultraviolet rays                    done clear
  B)
             Infrared rays done clear
  C)
             X-rays                                      done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer18)
  Which of the following waves have the maximum wavelength                                   [AFMC 2002]
  A)
             X-rays                                      done clear
  B)
             I.R. rays done clear
  C)
             UV rays                                   done clear
  D)
             Radio waves done clear
  View Solution play_arrow

• question_answer19)
  Electromagnetic waves are transverse in nature is evident by [AIEEE 2002]
  A)
             Polarisation                           done clear
  B)
             Interference done clear
  C)
             Reflection                              done clear
  D)
             Diffraction done clear
  View Solution play_arrow

• question_answer20)
  If \[\overrightarrow{E}\] and \[\overrightarrow{B}\] are the electric and magnetic field vectors of E.M. waves then the direction of propagation of E.M. wave is along the direction of [CBSE PMT 1992, 2002; DCE 2002, 05]
  A)
             \[\overrightarrow{E}\]     done clear
  B)
             \[\overrightarrow{B}\] done clear
  C)
             \[\overrightarrow{E}\times \overrightarrow{B}\]    done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer21)
  Biological importance of Ozone layer is         [CBSE PMT 2001]
  A)
             It stops ultraviolet rays done clear
  B)
             Ozone rays reduce greenhouse effect done clear
  C)
             Ozone layer reflects radio waves done clear
  D)
             Ozone layer controls \[{{O}_{2}}/{{H}_{2}}\] radio in atmosphere done clear
  View Solution play_arrow

• question_answer22)
  What is ozone hole                                                      [AFMC 2001]
  A)
             Hole in the ozone layer    done clear
  B)
             Formation of ozone layer done clear
  C)
             Thinning of ozone layer in troposphere done clear
  D)
             Reduction in ozone thickness in stratosphere done clear
  View Solution play_arrow

• question_answer23)
  Which rays are not the portion of electromagnetic spectrum       [Haryana CEET 2000]
  A)
             X-rays                                      done clear
  B)
             Microwaves done clear
  C)
             a-rays                                      done clear
  D)
             Radio waves done clear
  View Solution play_arrow

• question_answer24)
  Radio wave diffract around building although light waves do not. The reason is that radio waves                [AMU 2000]
  A)
             Travel with speed larger than c done clear
  B)
             Have much larger wavelength than light done clear
  C)
             Carry news done clear
  D)
             Are not electromagnetic waves done clear
  View Solution play_arrow

• question_answer25)
  The frequencies of X-rays, g-rays and ultraviolet rays are respectively a, b and c. Then    [CBSE PMT 2000]
  A)
             a < b, b > c                             done clear
  B)
             a > b, b > c done clear
  C)
             a > b, b < c                             done clear
  D)
             a < b, b < c done clear
  View Solution play_arrow

• question_answer26)
  Radio waves and visible light in vacuum have     [KCET 2000]
  A)
             Same velocity but different wavelength done clear
  B)
             Continuous emission spectrum done clear
  C)
             Band absorption spectrum     done clear
  D)
             Line emission spectrum done clear
  View Solution play_arrow

• question_answer27)
  Energy stored in electromagnetic oscillations is in the form of     [Haryana CEET 2000; AFMC 1994]
  A)
             Electrical energy                  done clear
  B)
             Magnetic energy done clear
  C)
             Both (a) and (b) done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer28)
  Heat radiations propagate with the speed of     [AMU 2000]
  A)
             a-rays                                      done clear
  B)
             b-rays done clear
  C)
             Light waves                           done clear
  D)
             Sound waves done clear
  View Solution play_arrow

• question_answer29)
    If a source is transmitting electromagnetic wave of frequency \[8.2\times {{10}^{6}}\]Hz, then wavelength of the electromagnetic waves transmitted from the source will be                        [DPMT 1999]
  A)
             36.6 m                                      done clear
  B)
             40.5 m done clear
  C)
             42.3 m                                      done clear
  D)
             50.9 m done clear
  View Solution play_arrow

• question_answer30)
  In an apparatus, the electric field was found to oscillate with an amplitude of 18 V/m. The magnitude of the oscillating magnetic field will be                                               [Pb. PMT 1999]
  A)
             \[4\times {{10}^{-6}}\]T   done clear
  B)
             \[6\times {{10}^{-8}}\]T done clear
  C)
             \[9\times {{10}^{-9}}\]T   done clear
  D)
             \[11\times {{10}^{-11}}\]T done clear
  View Solution play_arrow

• question_answer31)
  According to Maxwell?s hypothesis, a changing electric field gives rise to                                               [AIIMS 1998]
  A)
             An e.m.f.                                done clear
  B)
             Electric current done clear
  C)
             Magnetic field                      done clear
  D)
             Pressure radiant done clear
  View Solution play_arrow

• question_answer32)
  In an electromagnetic wave, the electric and magnetising fields are \[100\,V\,{{m}^{-1}}\] and \[0.265\,A\,{{m}^{-1}}\]. The maximum energy flow is                                  [Pb. PMT 1997, 98]
  A)
             \[26.5\,W/{{m}^{2}}\]       done clear
  B)
             \[36.5\,W/{{m}^{2}}\] done clear
  C)
             \[46.7\,W/{{m}^{2}}\]       done clear
  D)
             \[765\,W/{{m}^{2}}\] done clear
  View Solution play_arrow

• question_answer33)
  The 21 cm radio wave emitted by hydrogen in interstellar space is due to the interaction called the hyperfine interaction is atomic hydrogen. the energy of the emitted wave is nearly                                         [CBSE PMT 1998]
  A)
             \[{{10}^{-17}}\]Joule          done clear
  B)
             1 Joule done clear
  C)
             \[7\times {{10}^{-8}}\]Joule   done clear
  D)
             \[{{10}^{-24}}\]Joule done clear
  View Solution play_arrow

• question_answer34)
  TV waves have a wavelength range of 1-10 meter. Their frequency range in MHz is                                          [KCET 1998]
  A)
             30-300                                      done clear
  B)
             3-30 done clear
  C)
             300-3000                                 done clear
  D)
             3-3000 done clear
  View Solution play_arrow

• question_answer35)
  Maxwell?s equations describe the fundamental laws of [CPMT 1996]
  A)
             Electricity only                      done clear
  B)
             Magnetism only done clear
  C)
             Mechanics only                    done clear
  D)
             Both (a) and (b) done clear
  View Solution play_arrow

• question_answer36)
  The oscillating electric and magnetic vectors of an electromagnetic wave are oriented along [CBSE PMT 1994]
  A)
             The same direction but differ in phase by 90° done clear
  B)
             The same direction and are in phase done clear
  C)
             Mutually perpendicular directions and are in phase done clear
  D)
             Mutually perpendicular directions and differ in phase by 90° done clear
  View Solution play_arrow

• question_answer37)
  In which one of the following regions of the electromagnetic spectrum will the vibrational motion of molecules give rise to absorption                                                                        [SCRA 1994]
  A)
             Ultraviolet                              done clear
  B)
             Microwaves done clear
  C)
             Infrared                                  done clear
  D)
             Radio waves done clear
  View Solution play_arrow

• question_answer38)
  An electromagnetic wave travels along z-axis. Which of the following pairs of space and time varying fields would generate such a wave                                                              [CBSE PMT 1994]
  A)
             \[{{E}_{x}},\,{{B}_{y}}\]    done clear
  B)
             \[{{E}_{y}},\,{{B}_{x}}\] done clear
  C)
             \[{{E}_{z}},\,{{B}_{x}}\]    done clear
  D)
             \[{{E}_{y}},\,{{B}_{z}}\] done clear
  View Solution play_arrow

• question_answer39)
  Which of the following rays has the maximum frequency [CBSE PMT 1994]
  A)
             Gamma rays                          done clear
  B)
             Blue light done clear
  C)
             Infrared rays                         done clear
  D)
             Ultraviolet rays done clear
  View Solution play_arrow

• question_answer40)
  A signal emitted by an antenna from a certain point can be received at another point of the surface in the form of [CPMT 1993]
  A)
             Sky wave                                done clear
  B)
             Ground wave done clear
  C)
             Sea wave                                done clear
  D)
             Both (a) and (b) done clear
  View Solution play_arrow

• question_answer41)
  Approximate height of ozone layer above the ground is [CBSE PMT 1991]
  A)
             60 to 70 km                            done clear
  B)
             59 km to 80 km done clear
  C)
             70 km to 100 km                  done clear
  D)
             100 km to 200 km done clear
  View Solution play_arrow

• question_answer42)
  The electromagnetic waves do not transport [Pb. PET 1991]
  A)
             Energy                                     done clear
  B)
             Charge done clear
  C)
             Momentum                          done clear
  D)
             Information done clear
  View Solution play_arrow

• question_answer43)
  A plane electromagnetic wave is incident on a material surface. If the wave delivers momentum p and energy E, then
  A)
             p = 0, E = 0                              done clear
  B)
             p ¹ 0, E ¹ 0 done clear
  C)
             p ¹ 0, E = 0                              done clear
  D)
             p = 0, E ¹ 0 done clear
  View Solution play_arrow

• question_answer44)
  An electromagnetic wave, going through vacuum is described by \[E={{E}_{0}}\sin (kx-\omega \,t)\]. Which of the following is independent of wavelength
  A)
             k     done clear
  B)
             w done clear
  C)
             k/w                                           done clear
  D)
             kw done clear
  View Solution play_arrow

• question_answer45)
  An electromagnetic wave going through vacuum is described by \[E={{E}_{0}}\sin (kx-\omega \,t)\]; \[B={{B}_{0}}\sin (kx-\omega \,t)\]. Which of the following equation is true
  A)
             \[{{E}_{0}}k={{B}_{0}}\omega \]                                      done clear
  B)
             \[{{E}_{0}}\omega ={{B}_{0}}k\] done clear
  C)
             \[{{E}_{0}}{{B}_{0}}=\omega k\]                                      done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer46)
  An LC resonant circuit contains a 400 pF capacitor and a 100 mH inductor. It is set into oscillation coupled to an antenna. The wavelength of the radiated electromagnetic waves is
  A)
             377 mm                                   done clear
  B)
             377 metre done clear
  C)
             377 cm                                     done clear
  D)
             3.77 cm done clear
  View Solution play_arrow

• question_answer47)
  A radio receiver antenna that is 2 m long is oriented along the direction of the electromagnetic wave and receives a signal of intensity\[5\times {{10}^{-16}}W/{{m}^{2}}\]. The maximum instantaneous potential difference across the two ends of the antenna is
  A)
             1.23 mV                                    done clear
  B)
             1.23 mV done clear
  C)
             1.23 V                                       done clear
  D)
             12.3 mV done clear
  View Solution play_arrow

• question_answer48)
  Television signals broadcast from the moon can be received on the earth while the TV broadcast from Delhi cannot be received at places about 100 km distant from Delhi. This is because
  A)
             There is no atmosphere around the moon done clear
  B)
             Of strong gravity effect on TV signals done clear
  C)
             TV signals travel straight and cannot follow the curvature of the earth done clear
  D)
             There is atmosphere around the earth done clear
  View Solution play_arrow

• question_answer49)
  A TV tower has a height of 100 m. The average population density around the tower is 1000 per km2. The radius of the earth is \[6.4\times {{10}^{6}}\]m. the population covered by the tower is
  A)
             \[2\times {{10}^{6}}\]       done clear
  B)
             \[3\times {{10}^{6}}\] done clear
  C)
             \[4\times {{10}^{6}}\]       done clear
  D)
             \[6\times {{10}^{6}}\] done clear
  View Solution play_arrow

• question_answer50)
  The wavelength 21 cm emitted by atomic hydrogen in interstellar space belongs to
  A)
             Radio waves                          done clear
  B)
             Infrared waves done clear
  C)
             Microwaves                          done clear
  D)
             g-rays done clear
  View Solution play_arrow

• question_answer51)
  Which scientist experimentally proved the existence of electromagnetic waves                                                [AFMC 2004]
  A)
             Sir J.C. Bose                           done clear
  B)
             Maxwell done clear
  C)
             Marconi                                  done clear
  D)
             Hertz done clear
  View Solution play_arrow

• question_answer52)
  An electromagnetic wave of frequency \[\nu =3.0\,MHz\] passes from vacuum into a dielectric medium with permitivity \[\varepsilon =4.0\]. Then                                         [AIEEE 2004]
  A)
             Wavelength is doubled and the frequency remains unchanged done clear
  B)
             Wavelength is doubled and frequency becomes half done clear
  C)
             Wavelength is halved and frequency remains unchanged done clear
  D)
             Wavelength and frequency both remain unchanged done clear
  View Solution play_arrow

• question_answer53)
  Frequency of a wave is \[6\times {{10}^{15}}Hz.\] The wave is [Orissa PMT 2004]
  A)
             Radiowave                             done clear
  B)
             Microwave done clear
  C)
             X-ray                                        done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer54)
  The region of the atmosphere above troposphere is known as                                                                  [BCECE 2004]
  A)
             Lithosphere                           done clear
  B)
             Uppersphere done clear
  C)
             Ionosphere                           done clear
  D)
             Stratosphere done clear
  View Solution play_arrow

• question_answer55)
  Which of the following electromagnetic waves have minimum frequency                                             [Pb PET 2000]
  A)
             Microwaves                          done clear
  B)
             Audible waves done clear
  C)
             Ultrasonic waves                 done clear
  D)
             Radiowaves done clear
  View Solution play_arrow

• question_answer56)
  Which one of the following have minimum wavelength   [Pb PET 2001]
  A)
             Ultraviolet rays                    done clear
  B)
             Cosmic rays done clear
  C)
             X-rays                                      done clear
  D)
             \[\gamma -\]rays done clear
  View Solution play_arrow

• question_answer57)
  Radiations of intensity \[0.5\,\,W/{{m}^{2}}\] are striking a metal plate. The pressure on the plate is                       [DCE 2004]
  A)
             \[0.166\times {{10}^{-8}}\,N/{{m}^{2}}\]                     done clear
  B)
             \[0.332\times {{10}^{-8}}\,N/{{m}^{2}}\] done clear
  C)
             \[0.111\times {{10}^{-8}}\,N/{{m}^{2}}\]                     done clear
  D)
             \[0.083\times {{10}^{-8}}\,N/{{m}^{2}}\] done clear
  View Solution play_arrow

• question_answer58)
  Electromagnetic waves travel in a medium which has relative permeability 1.3 and relative permittivity 2.14. Then the speed of the electromagnetic wave in the medium will be                                                           [MH CET 2003]
  A)
             \[13.6\times {{10}^{6}}\,m/s\]                                          done clear
  B)
             \[1.8\times {{10}^{2}}\,m/s\] done clear
  C)
             \[3.6\times {{10}^{8}}\,m/s\]                                            done clear
  D)
             \[1.8\times {{10}^{8}}\,m/s\] done clear
  View Solution play_arrow

• question_answer59)
  The intensity of gamma radiation from a given source is I. On passing through 36 mm of lead, it is reduced to \[\frac{I}{8}\]. The thickness of lead which will reduce the intensity to \[\frac{I}{2}\] will be [AIEEE 2005]
  A)
              18 mm                                      done clear
  B)
              12 mm done clear
  C)
              6 mm                                         done clear
  D)
              9 mm done clear
  View Solution play_arrow

• question_answer60)
  If \[{{\lambda }_{v}},\,{{\lambda }_{r}}\] and \[{{\lambda }_{m}}\] represent the wavelength of visible light x-rays and microwaves respectively, then [CBSE PMT 2005]
  A)
             \[{{\lambda }_{m}}>{{\lambda }_{x}}>{{\lambda }_{v}}\]   done clear
  B)
             \[{{\lambda }_{v}}>{{\lambda }_{m}}>{{\lambda }_{y}}\] done clear
  C)
             \[{{\lambda }_{m}}>{{\lambda }_{v}}>{{\lambda }_{v}}\]   done clear
  D)
             \[{{\lambda }_{v}}>{{\lambda }_{x}}>{{\lambda }_{m}}\] done clear
  View Solution play_arrow

• question_answer61)
  For skywave propagation of a 10 MHz signal, what should be the minimum electron density in ionosphere [AFMC 2005]
  A)
             \[\tilde{\ }1.2\times {{10}^{12}}{{m}^{-3}}\]               done clear
  B)
             \[\tilde{\ }{{10}^{6}}{{m}^{-3}}\] done clear
  C)
             \[\tilde{\ }{{10}^{14}}{{m}^{-3}}\]                                   done clear
  D)
             \[\tilde{\ }{{10}^{22}}{{m}^{-3}}\] done clear
  View Solution play_arrow

• question_answer62)
  The pressure exerted by an electromagnetic wave of intensity I (watts/m2) on a nonreflecting surface is [c is the velocity of light]                                                                                         [AFMC 2005]
  A)
             \[Ic\]                                        done clear
  B)
             \[I{{c}^{2}}\] done clear
  C)
             \[I/c\] done clear
  D)
             \[I/{{c}^{2}}\] done clear
  View Solution play_arrow

• question_answer63)
  Infrared radiation was discovered in 1800 by [KCET 2005]
  A)
             William Wollaston               done clear
  B)
             William Herschel done clear
  C)
             Wilhelm Roentgen             done clear
  D)
             Thomas Young done clear
  View Solution play_arrow

• question_answer64)
  Which of the following is electromagnetic wave  [BCECE 2005]
  A)
             X-rays and light waves done clear
  B)
             Cosmic rays and sound waves done clear
  C)
             Beta rays and sound waves    done clear
  D)
             Alpha rays and sound waves done clear
  View Solution play_arrow

• question_answer65)
  Which one of the following is not electromagnetic in nature [Kerala PMT 2005]
  A)
             X-rays                                      done clear
  B)
             Gamma rays done clear
  C)
             Cathode rays                        done clear
  D)
             Infrared rays done clear
  View Solution play_arrow

• question_answer66)
  Light wave is travelling along y-direction. If the corresponding \[\vec{E}\] vector at any time is along the x-axis, the direction of \[\vec{B}\] vector at that time is along [UPSEAT 2005]
  A)
             y-axis done clear
  B)
             x-axis done clear
  C)
             + z-axis done clear
  D)
             ? z axis done clear
  View Solution play_arrow

• question_answer67)
  If c is the speed of electromagnetic waves in vacuum, its speed in a medium of dielectric constant K and relative permeability \[{{\mu }_{r}}\] is                                                                  [Kerala PET 2005]
  A)
             \[v=\frac{1}{\sqrt{{{\mu }_{r}}K}}\]                                done clear
  B)
             \[v=c\sqrt{{{\mu }_{r}}K}\] done clear
  C)
             \[v=\frac{c}{\sqrt{{{\mu }_{r}}K}}\]                                done clear
  D)
             \[v=\frac{K}{\sqrt{{{\mu }_{r}}C}}\] done clear
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