12th Class Physics Current Electricity, Charging & Discharging Of Capacitors / वर्तमान बिजली, चार्ज और कैपेसिटर का निर Question Bank

done MCQ - Current Electricity Total Questions - 105

• question_answer1)
  Lighting is an electrical discharge caused by imbalanced between
  A)
  clouds and the ground done clear
  B)
  within the clouds done clear
  C)
  Both a and b         done clear
  D)
  None of these done clear
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• question_answer2)
  Electric current has both magnitude and direction it is a:
  A)
  vector quantity      done clear
  B)
  scalar quantity done clear
  C)
  tensor quantity      done clear
  D)
  None of these done clear
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• question_answer3)
  Conventional current flows from
  A)
  point of higher potential to lower potential done clear
  B)
  point of lower potential to higher potential done clear
  C)
  point of lower potential to lower potential done clear
  D)
  all of the above done clear
  View Solution play_arrow

• question_answer4)
  One coulomb per second is equal to:
  A)
  1 farad                          done clear
  B)
  1 ampere done clear
  C)
  1 volt               done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer5)
  A charge of 60 C passes through an electric lamp in 2 minutes. Then the current in the lamp is:
  A)
  30 A                             done clear
  B)
  1 A done clear
  C)
  0.5 A                            done clear
  D)
  5 A done clear
  View Solution play_arrow

• question_answer6)
  Charge through a conductor is given as a function of time t as \[q=4{{t}^{2}}+4t+4\] coulomb. At 2 s what is the current flowing?
  A)
  12 A                 done clear
  B)
  8 A done clear
  C)
  20 A                done clear
  D)
  28 A done clear
  View Solution play_arrow

• question_answer7)
  Charge through a cross-section of a conductor is given by \[Q=5{{t}^{2}}-2t\]. It coulomb. Find the average current through the conductor in the interval \[{{t}_{1}}=2\,s\]to\[{{t}_{2}}=4\,s\].
  A)
  14 A                             done clear
  B)
  28A    done clear
  C)
  56 A                             done clear
  D)
  7 A done clear
  View Solution play_arrow

• question_answer8)
  The current in a wire varies with time according to the equation\[l=4+2t\], where, l is an ampere and f is in second. The quantity of charge which has to be passed through a cross-section of the wire during the time t =2s to t = 6s is:
  A)
  40 C                 done clear
  B)
  48 C    done clear
  C)
  38 C                             done clear
  D)
  43 C done clear
  View Solution play_arrow

• question_answer9)
  An electric charge will experience a ........... when an electric field is applied.
  A)
  pressure            done clear
  B)
  momentum done clear
  C)
  force                 done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer10)
  In earth's atmosphere where do the free charged particles exist?
  A)
  ionosphere                     done clear
  B)
  mesosphere done clear
  C)
  troposphere          done clear
  D)
  stratosphere  done clear
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• question_answer11)
                           Mechanisms which maintain a steady electric field are:
  A)
  cells                 done clear
  B)
  batteries done clear
  C)
  Both (a) and (b)      done clear
  D)
     None of these done clear
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• question_answer12)
  In the current against voltage curve in Ohm's law, the slope gives:
  A)
  resistance                       done clear
  B)
  conductance done clear
  C)
  resistivity                       done clear
  D)
  conductivity done clear
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• question_answer13)
  The electrical resistance of a conductor depends upon:
  A)
  size of the conductor done clear
  B)
  temperature of the conductor done clear
  C)
  geometry of the conductor done clear
  D)
  All of the above done clear
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• question_answer14)
  The voltage V and current l graphs for a conductor at two different temperatures \[{{T}_{1}}\]and \[{{T}_{2}}\]are shown in the figure. The relation between \[{{T}_{1}}\]and \[{{T}_{2}}\]is:
  A)
  \[{{T}_{1}}>{{T}_{2}}\]                     done clear
  B)
  \[{{T}_{1}}<{{T}_{2}}\] done clear
  C)
  \[{{T}_{1}}={{T}_{2}}\]                done clear
  D)
  \[{{T}_{1}}=\frac{1}{{{T}_{2}}}\] done clear
  View Solution play_arrow

• question_answer15)
  A 220 V main supply is connected to a resistance of\[100\,k\Omega \]. The effective current is
  A)
  \[2.2\,mA\]                        done clear
  B)
  \[2.2\sqrt{2}\,mA\] done clear
  C)
  \[\frac{2.2}{\sqrt{2}}\,mA\]                    done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer16)
  Consider a current carrying wire (current I) in the shape of a circle. Note that as the current progresses along the wire, the direction of \[\overrightarrow{J}\] (current density) changes in an exact manner, while the current / remains unaffected. The agent that is essentially responsible for it is:                                                                   (NCERT EXEMPLAR)
  A)
  source of emf done clear
  B)
  electric field produced by charges accumulated on the surface of wire done clear
  C)
  the charges just behind a given segment of wire which push them just right way by repulsion done clear
  D)
  the charges ahead done clear
  View Solution play_arrow

• question_answer17)
  In the diagram shown, the reading of voltmeter is 20 V and that of ammeter is 4 A. The value of R should be (Consider given ammeter and voltmeter are not ideal):
  A)
  equal to \[5\Omega \]         done clear
  B)
      greater than \[5\Omega \] done clear
  C)
  less than \[5\Omega \]           done clear
  D)
    greater or less than \[5\Omega \] done clear
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• question_answer18)
  There are three copper wires of equal length and the ratio of their radii is \[1:2:3\]. What is the ratio of their resistivity?
  A)
  \[1:2:3\]                         done clear
  B)
  \[3:2:1\]                   done clear
  C)
  \[1:1:1\]              done clear
  D)
  \[1:4:9\]                     done clear
  View Solution play_arrow

• question_answer19)
                                      The condition for the validity of Ohm's law is that the:
  A)
  temperature should remain constant done clear
  B)
  current should be proportional to voltage done clear
  C)
  resistance must be wire wound type done clear
  D)
  all of the above done clear
  View Solution play_arrow

• question_answer20)
  The unit of specific conductivity is:
  A)
  \[\Omega -c{{m}^{-1}}\]                      done clear
  B)
  \[\Omega -c{{m}^{2}}\] done clear
  C)
  \[{{\Omega }^{-1}}cm\]                       done clear
  D)
  \[{{\Omega }^{-1}}c{{m}^{-1}}\] done clear
  View Solution play_arrow

• question_answer21)
  A metal rod of Length 10 cm and a rectangular cross-section of \[\text{1}\,\text{cm }\!\!\times\!\!\text{ }\frac{\text{1}}{\text{2}}\] is connected to a battery across opposite faces. The resistance will be: (NCERT EXEMPLAR)
  A)
  maximum when the battery is connected across \[\text{1}\,\text{cm }\!\!\times\!\!\text{ }\frac{\text{1}}{\text{2}}\] faces done clear
  B)
  maximum when the battery is connected across \[\text{10}\,\text{cm }\!\!\times\!\!\text{ 1}\,\text{cm}\]faces                                        done clear
  C)
  maximum when the battery is connected across \[\text{10}\,\text{cm }\!\!\times\!\!\text{ }\frac{\text{1}}{2}\,\text{cm}\] faces                                      done clear
  D)
  same irrespective of the three faces done clear
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• question_answer22)
  The resistance of a wire is \[10\Omega \]. What will be the new resistance, if it is stretched uniformly 8 times its original length?
  A)
  \[640\,\Omega \]                         done clear
  B)
  \[64\,\Omega \] done clear
  C)
  \[10\,\Omega \]                           done clear
  D)
  \[6400\,\Omega \] done clear
  View Solution play_arrow

• question_answer23)
  A cylindrical rod is reformed to half of its original Length keeping volume constant. If its resistance before this change were R, then the resistance after reformation of rod will be:
  A)
  R                     done clear
  B)
  R/4 done clear
  C)
  3R/4                              done clear
  D)
  R/2 done clear
  View Solution play_arrow

• question_answer24)
  The conductivity of a metal decreases with the increase in temperature on account of:                 (CBSE 2020)
  A)
  decrease in number density of electrons done clear
  B)
  decrease in resistivity done clear
  C)
  decrease in relaxation time done clear
  D)
  increase in mean free path done clear
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• question_answer25)
  The figure shows three cylindrical copper conductors along with their face areas and lengths. Rank them according to the current through them, greatest first when the same potential difference V is placed across their lengths.
  A)
  \[{{i}_{l}}={{i}_{ll}}={{i}_{lll}}\]                   done clear
  B)
  \[{{i}_{l}}>{{i}_{ll}}>{{i}_{lll}}\] done clear
  C)
  \[{{i}_{l}}<{{i}_{ll}}<{{i}_{lll}}\]                   done clear
  D)
  \[({{i}_{l}}={{i}_{lll}})<{{i}_{ll}}\] done clear
  View Solution play_arrow

• question_answer26)
  When there is an electric current through a conducting wire along its length, then an electric field must exist:
  A)
  outside the wire but normal to it                       done clear
  B)
  outside the wire but parallel to it done clear
  C)
  inside the wire but parallel to it done clear
  D)
  inside the wire but normal to it done clear
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• question_answer27)
  Which of the following characteristics of electrons determines the current in a conductor?          (NCERT EXEMPLAR)
  A)
  Drift velocity alone done clear
  B)
  Thermal velocity alone done clear
  C)
  Both drift velocity and thermal velocity done clear
  D)
  Neither drift nor thermal velocity done clear
  View Solution play_arrow

• question_answer28)
                         Drift velocity \[{{\text{v}}_{\text{d}}}\] varies with the intensity of electric field as per the relation:
  A)
  \[{{\text{v}}_{\text{d}}}\propto E\]                    done clear
  B)
  \[{{\text{v}}_{\text{d}}}\propto \frac{1}{E}\] done clear
  C)
  \[{{\text{v}}_{\text{d}}}\text{=constant}\]                     done clear
  D)
  \[{{\text{v}}_{\text{d}}}\propto {{E}^{2}}\] done clear
  View Solution play_arrow

• question_answer29)
  The unit of mobility is
  A)
  \[m{{s}^{-1}}\]                        done clear
  B)
  \[m{{s}^{-1}}V\] done clear
  C)
  \[{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\]             done clear
  D)
  \[{{m}^{2}}{{V}^{-1}}s\] done clear
  View Solution play_arrow

• question_answer30)
  A steady current flows in a metallic conductor of non-uniform cross-section. The quantity/quantities constant along the length of the conductor is/are:
  A)
  current, electric field and drift speed done clear
  B)
  drift speed only done clear
  C)
  current and drift speed done clear
  D)
  current only done clear
  View Solution play_arrow

• question_answer31)
  A charged particle having drift velocity of \[7.5\times {{10}^{-4}}m{{s}^{-1}}\] in electric field of \[3\times {{10}^{-10}}V{{m}^{-1}}\], mobility is:
  A)
  \[6.5\times {{10}^{6}}{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\]  done clear
  B)
      \[2.5\times {{10}^{6}}{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\] done clear
  C)
  \[2.5\times {{10}^{4}}{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\]   done clear
  D)
  \[6.5\times {{10}^{4}}{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\] done clear
  View Solution play_arrow

• question_answer32)
  The resistance of a metal wire increases with increasing temperature on account of:                  (CBSE 2020)
  A)
  decrease in free electron density done clear
  B)
  decrease in relaxation time done clear
  C)
  increase in mean free path done clear
  D)
  increase in the mass of electron done clear
  View Solution play_arrow

• question_answer33)
  The dimensions of mobility of charge carriers are:
  A)
  \[\left[ {{M}^{-2}}{{T}^{2}}A \right]\]             done clear
  B)
  \[\left[ {{M}^{-1}}{{T}^{2}}A \right]\] done clear
  C)
  \[\left[ {{M}^{-2}}{{T}^{3}}A \right]\]             done clear
  D)
  \[\left[ {{M}^{-1}}{{T}^{3}}A \right]\] done clear
  View Solution play_arrow

• question_answer34)
  Which of the following I-V graph represents ohmic conductors?
  A)
  done clear
  B)
  done clear
  C)
         done clear
  D)
  done clear
  View Solution play_arrow

• question_answer35)
      Ohm's Law is not applicable to:
  A)
  dc circuits                      done clear
  B)
  high currents done clear
  C)
  small resistors        done clear
  D)
  semi-conductors             done clear
  View Solution play_arrow

• question_answer36)
  The I-V characteristics shown In figure represents:
  A)
  ohmic conductors   done clear
  B)
  non-ohmic conductors done clear
  C)
  insulators           done clear
  D)
  superconductors done clear
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• question_answer37)
  Ohm's law fails in:
  A)
  Diode                done clear
  B)
  Thyristor                 done clear
  C)
      PN junction system done clear
  D)
                All of these                   done clear
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• question_answer38)
  Range of resistivity for metals is:                        
  A)
  \[{{10}^{-6}}\Omega m\text{ }to\text{ }{{10}^{-4}}\Omega m\]  done clear
  B)
  \[{{10}^{-7}}\Omega m\text{ }to\text{ }{{10}^{-5}}\Omega m\] done clear
  C)
  \[{{10}^{-8}}\Omega m\text{ }to\text{ }{{10}^{-6}}\Omega m\] done clear
  D)
  \[{{10}^{-9}}\Omega m\text{ }to\text{ }{{10}^{-7}}\Omega m\] done clear
  View Solution play_arrow

• question_answer39)
  Which meterial is expected to have least resistivity?     
  A)
  Copper                          done clear
  B)
  Lead    done clear
  C)
  Mercury                         done clear
  D)
  Zinc done clear
  View Solution play_arrow

• question_answer40)
                                           A copper wire is stretched to make it 0.2%. What is the percentage change in its resistivity?                  
  A)
  0.4%                 done clear
  B)
  2.0%                    done clear
  C)
  4.0%                 done clear
  D)
  None of these              done clear
  View Solution play_arrow

• question_answer41)
  Arrange the following materials in increasing order of their resistivity: Nichrome, Copper, Germanium, Silicon
  A)
  Copper < Nichrome < Germanium < Silicon done clear
  B)
  Germanium < Copper < Nichrome < Silicon done clear
  C)
  Nichrome < Copper < Germanium < Silicon done clear
  D)
  Silicon < Nichrome < Germanium < Copper done clear
  View Solution play_arrow

• question_answer42)
  The resistance of the fuse wire is:
  A)
  low          done clear
  B)
  moderate done clear
  C)
  zero                   done clear
  D)
  very high done clear
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• question_answer43)
  The temperature (T) dependence of resistivity \[(\rho )\] of a semiconductor is represented by:
  A)
  done clear
  B)
  done clear
  C)
        done clear
  D)
  done clear
  View Solution play_arrow

• question_answer44)
                          We use alloy for making of resistors, because they have
  A)

  Temp. coefficient	Resistivity
  Low	Low

  done clear
  B)

  High

  High

  done clear
  C)

  High

  Low

  done clear
  D)

  Low

  High

  done clear
  View Solution play_arrow

• question_answer45)
  The temperature coefficient of resistance of an alloy used for making resistors is:
  A)
  small and positive           done clear
  B)
  small and negative done clear
  C)
  large and positive    done clear
  D)
  large and negative done clear
  View Solution play_arrow

• question_answer46)
  The resistance of a heating element is \[99\,\Omega \]at room temperature. What is the temperature of the element, if the resistance is found to be \[116\,\Omega \]?                   (Temperature coefficient of the material of the resistor is \[1.7\times {{10}^{-4}}{}^\circ {{C}^{-1}}\])
  A)
  \[999.9{}^\circ C\]                    done clear
  B)
  \[1005.3{}^\circ C\] done clear
  C)
  \[1020.2{}^\circ C\]                   done clear
  D)
  \[1037.1{}^\circ C\] done clear
  View Solution play_arrow

• question_answer47)
  Identical piece of Ge and Cu are taken and cooled, then:
  A)
  resistivity of both increases                              done clear
  B)
  resistivity of both decreases                              done clear
  C)
  resistivity of Cu increases and Ge decreases done clear
  D)
  resistivity of Cu decreases and Ge increases done clear
  View Solution play_arrow

• question_answer48)
  Which of the following is wrong? Resistivity of a conductor is:
  A)
  independent of temperature done clear
  B)
  inversely proportional to temperature                  done clear
  C)
  Independent of dimensions of conductor               done clear
  D)
  less than resistivity of a semiconductor                 done clear
  View Solution play_arrow

• question_answer49)
            A wire has a resistance of \[2.5\,\Omega \] at \[28{}^\circ C\] and a resistance of \[2.9\,\Omega \] at \[100{}^\circ C\]. The temperature coefficient of resistivity of material of the wire is:
  A)
  \[1.06\times {{10}^{-3}}{}^\circ {{C}^{-1}}\]       done clear
  B)
  \[3.5\times {{10}^{-2}}\,{}^\circ {{C}^{-1}}\] done clear
  C)
  \[2.22\times {{10}^{-3}}\text{ }{}^\circ {{C}^{-1}}\]              done clear
  D)
  \[3.95\times {{10}^{-2}}\text{ }{}^\circ {{C}^{-1}}\] done clear
  View Solution play_arrow

• question_answer50)
  Joule's law of heating effect can be expressed as:
  A)
  \[H=\frac{{{V}^{2}}}{R}t\]                 done clear
  B)
  \[H=\frac{{{l}^{2}}}{R}t\] done clear
  C)
  \[H={{V}^{2}}Rt\]                  done clear
  D)
  \[H=lRt\] done clear
  View Solution play_arrow

• question_answer51)
  A current of 2 A flows in a wire offering a resistance of \[10\,\Omega \]. Calculate the energy dissipated by the wire in 0.5 hours.
  A)
  72 Wh               done clear
  B)
  72 kJ done clear
  C)
  7200 J               done clear
  D)
  72 kJh done clear
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• question_answer52)
  A bulb has a power of 200 W. What is the energy dissipated by it in 5 minutes?
  A)
  60 J                  done clear
  B)
  1000 J   done clear
  C)
  60 kJ                 done clear
  D)
  1 kJ done clear
  View Solution play_arrow

• question_answer53)
  A boy has two spare light bulbs in his drawer. One is marked 240 V and 100 W and the other is marked 240 V and 60 W. He tries to decide which of the following assertions are correct?
  A)
  The 60 W light bulb has more resistance and therefore burns less brightly done clear
  B)
  The 60 W light bulb has less resistance and therefore burns less brightly done clear
  C)
  The 100 W bulb has more resistance and therefore burns more brightly done clear
  D)
  The 100 W bulb has less resistance and therefore bums less brightly done clear
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• question_answer54)
                                 Two resistors \[{{R}_{1}}\] and \[{{R}_{2}}\] of \[4\,\Omega \] and \[6\,\Omega \] are connected in parallel across a battery. The ratio of power dissipated in them, \[{{P}_{1}}:{{P}_{2}}\]will be:                                            (CBSE 2020)
  A)
  4:9                                done clear
  B)
  3:2                      done clear
  C)
  9:4                                done clear
  D)
  2:3                     done clear
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• question_answer55)
      Four wires of the same diameter are connected, in turn, between two points maintained at a constant potential difference. Their resistivities and lengths are; \[\rho \] and L (wire 1), \[1.2\text{ }\rho \] and 1.2 L (wire 2), \[0.9\text{ }\rho \] and 0.9 L (wire 3) and \[\rho \] and  1.5 L (wire 4). Rank the wires according to the rates at which energy is dissipated as heat, greatest first:
  A)
  4>3>1>2         done clear
  B)
  4>2>1>3              done clear
  C)
  1>2>3>4        done clear
  D)
  3>1>2>4              done clear
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• question_answer56)
  A heater coil is rated 100 W, 200 V. It is cut into two identical parts. Both parts are connected together in parallel, to the same source of 200 V. The energy Liberated per second in the new combination is:
  A)
  100 J                done clear
  B)
  200 J   done clear
  C)
  300 J                            done clear
  D)
  400J         done clear
  View Solution play_arrow

• question_answer57)
  In the circuit shown in figure, heat developed across \[2\,\Omega ,\,\,4\,\Omega \]. and \[3\,\Omega \] resistances are in the ratio of:
  A)
  2 : 4 : 3                         done clear
  B)
  8 : 4 : 12 done clear
  C)
  4 : 8 : 27               done clear
  D)
  8 : 4 : 27 done clear
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• question_answer58)
  A cell of emf E is connected with an external resistance R, then potential difference across cell is V. The internal resistance of cell will be:
  A)
  \[\frac{(E-V)R}{E}\]                    done clear
  B)
  \[\frac{(E-V)R}{V}\] done clear
  C)
  \[\frac{(V-E)R}{V}\]                   done clear
  D)
  \[\frac{(V-E)R}{E}\] done clear
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• question_answer59)
  About internal resistance of a cell, the correct statement is that it is:
  A)
  Constant for a given cell done clear
  B)
  Infinite done clear
  C)
  Finite and its value decreases with increase of time of use done clear
  D)
  Finite and its value increases with increase of time of use done clear
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• question_answer60)
  A cell having an emf \[\varepsilon \] and internal resistance r is connected across a variable external resistance R. As the resistance R is increased, the plot of potential difference V across R is given by:                                    
  A)
         done clear
  B)
  done clear
  C)
        done clear
  D)
  done clear
  View Solution play_arrow

• question_answer61)
  A battery of emf 15 V and internal resistance of \[4\text{ }\Omega \] is connected to a resistor. If the current in the circuit is 2 A and the circuit is close(d) Resistance of the resistor and terminal voltage of the battery will be:
  A)
  \[2.5\,\Omega .\text{ }6\text{ }V\]                       done clear
  B)
  \[3.5\text{ }\Omega ,\text{ }6\text{ }V\] done clear
  C)
  \[2.5\text{ }\Omega ,\text{ }7\text{ }V\]            done clear
  D)
                \[3.5\text{ }\Omega \text{ }7\text{ }V\] done clear
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• question_answer62)
  Two batteries of emf \[{{\varepsilon }_{1}}\] and \[{{\varepsilon }_{2}}({{\varepsilon }_{2}}>{{\varepsilon }_{1}})\] and internal resistances \[{{r}_{1}}\] and \[{{r}_{2}}\] respectively are connected in parallel as shown in figure.                                                                                                   (NCERT EXEMPLAR)
  A)
  The equivalent emf \[{{\varepsilon }_{eq}}\] of the two cells is between \[{{\varepsilon }_{1}}\] and \[{{\varepsilon }_{2}}\], i.e., \[{{\varepsilon }_{1}}<{{\varepsilon }_{eq}}<{{\varepsilon }_{2}}\] done clear
  B)
  The equivalent emf \[{{\varepsilon }_{eq}}\] is smaller than \[{{\varepsilon }_{1}}\] done clear
  C)
  The \[{{\varepsilon }_{eq}}\] is given by \[{{\varepsilon }_{eq}}={{\varepsilon }_{1}}+{{\varepsilon }_{2}}\] always done clear
  D)
  \[{{\varepsilon }_{eq}}\] is independent of internal resistances \[{{r}_{1}}\] and \[{{r}_{2}}\] done clear
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• question_answer63)
                     What is the internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of \[10\,\Omega \]?
  A)
  \[1\,\Omega \]                            done clear
  B)
  \[0.5\,\Omega \]   done clear
  C)
  \[2\,\Omega \]                            done clear
  D)
  \[3\,\Omega \] done clear
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• question_answer64)
  A cell of emf E and internal resistance r is connected across a resistance R. If internal resistance is equal to R, then the potential difference between the terminals of the cell must be:
  A)
  E                                  done clear
  B)
  \[\frac{E}{2}\] done clear
  C)
              \[\frac{E}{4}\]                           done clear
  D)
  \[\frac{3E}{2}\] done clear
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• question_answer65)
  Two batteries of emfs 2 V and 1 V of internal resistances \[1\,\Omega \] and \[2\,\Omega \] respectively are connected in parallel. The effective emf of the combination is:
  A)
  \[\frac{3}{2}V\]             done clear
  B)
  \[\frac{5}{3}V\] done clear
  C)
  \[\frac{3}{5}V\]                         done clear
  D)
  \[2\,V\] done clear
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• question_answer66)
  Current provided by a battery is maximum when
  A)
  internal resistance is equal to external resistance done clear
  B)
  internal resistance is greater than external resistance done clear
  C)
  internal resistance is less than external resistance done clear
  D)
  None of the above done clear
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• question_answer67)
  A cell supplies a current of 0.9 A through a \[2\,\Omega \]resistor and a current of 0.3 A through \[7\,\Omega \] resistor. The internal resistance of the cell is:
  A)
  \[2.0\,\Omega \]                     done clear
  B)
  \[1.5\,\Omega \] done clear
  C)
  \[1.0\,\Omega \]                      done clear
  D)
  \[0.5\,\Omega \] done clear
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• question_answer68)
    The battery of a trunk has an emf of 24 V. If the internal resistance of the battery is \[0.8\text{ }\Omega \]. What is the maximum current that can be drawn from the battery?
  A)
  30 A       done clear
  B)
  32 A done clear
  C)
  33 A                 done clear
  D)
  34 A done clear
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• question_answer69)
  A battery having 12 V emf and internal resistance \[3\,\Omega \] is connected to a resistor. If the current in the circuit is 1 A, then the resistance of resistor and lost voltage of the battery when circuit is closed will be:
  A)
  \[7\text{ }\Omega \text{, }7\text{ }V\]                done clear
  B)
  \[8\text{ }\Omega ,\,8\text{ }V\] done clear
  C)
  \[9\text{ }\Omega ,\text{ }9\text{ }V\]               done clear
  D)
  \[9\text{ }\Omega ,10\text{ }V\] done clear
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• question_answer70)
  Five cells each of emf E and resistance r are connected in series. Due to oversight one cell is connected wrongly. The equivalent emf and internal resistance of the combination is:
  A)
  5E                    done clear
  B)
  2E                        done clear
  C)
  3E                                done clear
  D)
  4E                         done clear
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• question_answer71)
                       Three identical cells, each of 4V and internal resistance r, are connected in series to a \[6\,\Omega \] resistor. If the current flowing in the circuit is 2 (A) The internal resistance of each cell is:
  A)
  \[0.11\,\Omega \]                   done clear
  B)
  \[0.\,\Omega \] done clear
  C)
  \[0.12\,\Omega \]                  done clear
  D)
  \[1.1\,\Omega \] done clear
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• question_answer72)
  In the electric circuit shown, each cell has an emf of 2 V and internal resistance is \[1\,\Omega \]. The external resistance is \[2\,\Omega \]. The value of the current l is (in ampere):
  A)
  2          done clear
  B)
    1.25 done clear
  C)
  0.4                                done clear
  D)
  1.2 done clear
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• question_answer73)
  If n identical cells of emf \[\varepsilon \]. and internal resistance r are connected in series, then the total emf and equivalent internal resistance of the combination will be:
  A)
  \[\varepsilon \frac{r}{n}\]                        done clear
  B)
  \[\varepsilon ,\,nr\]    done clear
  C)
  \[n\varepsilon ,\,\frac{r}{n}\]                   done clear
  D)
  \[n\varepsilon ,\,nr\] done clear
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• question_answer74)
  If n cells each of emf \[\varepsilon \] and internal resistance r are connected in parallel, then the total emf and internal resistances will be:
  A)
  \[\varepsilon ,\frac{r}{n}\]                       done clear
  B)
  \[\varepsilon ,nr\] done clear
  C)
  \[n\varepsilon ,\frac{r}{n}\]                     done clear
  D)
  \[n\varepsilon ,nr\] done clear
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• question_answer75)
  The basic laws for analyzing an electric circuit are:
  A)
  Einstein's theory      done clear
  B)
  Newton's laws done clear
  C)
  Kirchhoff's laws       done clear
  D)
  Faraday's laws              done clear
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• question_answer76)
                                      Kirchhoff's first and second laws are respectively based on law of conservation of:                                
  A)
  momentum and energy done clear
  B)
  charge and energy  done clear
  C)
         mass and energy     done clear
  D)
  None of the above        done clear
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• question_answer77)
                             The value of current l in figure is:
  A)
  4 A                  done clear
  B)
  6 A done clear
  C)
  3 A                  done clear
  D)
  5 A done clear
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• question_answer78)
  Figure shows currents in a part of an electric circuit, then current l is:
  A)
  1.7 A done clear
  B)
                3.7 A done clear
  C)
  1.3 A                            done clear
  D)
  1 A done clear
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• question_answer79)
                 In the given circuit the potential at point B is zero, the potential at points A and D will be:
  A)
  \[{{V}_{A}}=4\,V;{{V}_{D}}=9\,V\] done clear
  B)
  \[{{V}_{A}}=3\,V;{{V}_{D}}=4\,V\] done clear
  C)
  \[{{V}_{A}}=9\,V;{{V}_{D}}=3\,V\] done clear
  D)
  \[{{V}_{A}}=4\,V;{{V}_{D}}=3\,V\] done clear
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• question_answer80)
  In the circuit diagram, calculate the electric current through branch BC:
  A)
  4 A                   done clear
  B)
  2 A     done clear
  C)
  5 A                               done clear
  D)
  10 A done clear
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• question_answer81)
  Electric current through resistance \[10\text{ }\Omega \], in the given circuit is:
  A)
  0 A                  done clear
  B)
  0.5 A done clear
  C)
  6/11A                            done clear
  D)
  2A done clear
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• question_answer82)
  A 7 V battery with internal resistance \[2\,\Omega \] and a 3 V battery with internal resistance \[1\,\Omega \] are connected to a \[10\,\Omega \] resistor as shown in figure, the current in \[10\,\Omega \] resistor is:
  A)
  0.27 A                 done clear
  B)
  0.31 A done clear
  C)
  0.031 A                done clear
  D)
  0.53 A done clear
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• question_answer83)
  In a balanced Wheatstone's network, the resistances in arms Q and S are interchange(d) As a result of this:
  A)
  galvanometer and the cell must be interchanged to balance done clear
  B)
  galvanometer shows zero deflection done clear
  C)
  network is not balanced done clear
  D)
  network is still balanced                       done clear
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• question_answer84)
                 Wheatstone bridge works on the principle of..........      
  A)
  full deflection        done clear
  B)
  partial deflection     done clear
  C)
             no deflection          done clear
  D)
  null deflection                  done clear
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• question_answer85)
  WSB experiment is most sensitive, when:
  A)
  all four resistance are approximately equal done clear
  B)
  one of the resistance is very high as compare to others done clear
  C)
  one of the resistance is very low as compare to others done clear
  D)
  any two resistances are equal to infinity               done clear
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• question_answer86)
  In a Wheatstone's bridge, all the four arms have equal resistance R. If resistance of the galvanometer arm is also R, then equivalent resistance of the combination is:
  A)
  R                                  done clear
  B)
  2R                         done clear
  C)
  \[\frac{R}{2}\]                           done clear
  D)
  \[\frac{R}{4}\] done clear
  View Solution play_arrow

• question_answer87)
  In a Wheatstone bridge if the battery and galvanometer are interchanged, then the deflection in galvanometer will:
  A)
  change in previous direction done clear
  B)
  not change              done clear
  C)
  change in opposite direction              done clear
  D)
  None of the above        done clear
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• question_answer88)
     Determine the electric current through branch BD of the electric network:  
  A)
  0.6 A                     done clear
  B)
  0 A done clear
  C)
  1 A                       done clear
  D)
  10 A done clear
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• question_answer89)
  Four resistances of \[3\,\Omega ,\,3\,\Omega ,\,3\,\Omega \] and \[4\,\Omega \] respectively are used to a form of a Wheatstone bridge. The \[4\,\Omega \] resistance is short circuited with a resistance R in order to get bridge balanced. The value of R will be:
  A)
  \[10\,\Omega \]                    done clear
  B)
  \[11\,\Omega \] done clear
  C)
  \[12\,\Omega \]                           done clear
  D)
  \[13\,\Omega \] done clear
  View Solution play_arrow

• question_answer90)
  Four resistors are connected as shown in the figure. A 6 V battery of negligible resistance is connected across terminals A and C. The potential difference across terminals B and D will be:
  A)
  Zero                done clear
  B)
  1.5 V done clear
  C)
  2 V                  done clear
  D)
  3 V done clear
  View Solution play_arrow

• question_answer91)

  Consider the following statements regarding the network shown in the figure:

  1. The equivalent resistance of the network between points A and B is \[\left( \frac{4}{3}R \right)\].

  2. The current in resistor 3R is zero.

  3. The potential difference across R is equal to the potential difference across 2R.

  Which of the above statement(s) is/are correct?

  A)
  1 only                           done clear
  B)
  2 only                     done clear
  C)
       2 and 3                         done clear
  D)
  1, 2 and 3                     done clear
  View Solution play_arrow

• question_answer92)
  Meter bridge is application of:
  A)
  Kirchhoff's current law                                   done clear
  B)
  Kirchhoff's voltage law                                  done clear
  C)
  balance Wheatstone bridge                          done clear
  D)
  Both (a) and b,                          done clear
  View Solution play_arrow

• question_answer93)
                           The resistances in left and right gap of a meter bridge are \[20\,\Omega \] and \[30\,\Omega \] respectively. When the resistance in the left gap is reduced to half its value, the balance point shifts by:
  A)
  15 cm to the right   done clear
  B)
    15 cm to the left done clear
  C)
          20 cm to the right    done clear
  D)
  20 cm to the left              done clear
  View Solution play_arrow

• question_answer94)
  A resistance R is to be measured using a meter bridge. Student chooses the standard resistance S to be \[100\text{ }\Omega \]. He finds the null point at \[{{l}_{1}}=2.9\,cm\]. He is told to attempt to improve the accuracy. Which of the following is a useful Way?                                                                                                                   (NCERT EXEMPLAR)
  A)
  He should measure \[{{l}_{1}}\] more accurately done clear
  B)
  He should change S to \[1000\text{ }\Omega \]and repeat the experiment done clear
  C)
  He should change S to \[\text{3 }\Omega \] and repeat the experiment done clear
  D)
  He should give up hope of a more accurate measurement with a meter bridge done clear
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• question_answer95)
  In a meter bridge experiment, the ratio of the left gap resistance to right gap resistance is 2 : 3, the balance point from left is:
  A)
  60 cm               done clear
  B)
  50 cm   done clear
  C)
  40 cm                           done clear
  D)
  20 cm done clear
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• question_answer96)
  In a metre bridge experiment, resistance box (with \[R=2\text{ }\Omega \]) is connected in the left gap and the unknown resistance S in the right gap. If balancing length be 40 cm, calculate value of S.
  A)
  \[\text{2 }\Omega \]                    done clear
  B)
  \[\text{3 }\Omega \] done clear
  C)
  \[\text{4 }\Omega \]                                done clear
  D)
  \[\text{2}\text{.5 }\Omega \] done clear
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• question_answer97)
  What is the value of unknown resistance R, if galvanometer shows null deflection in the given meter bridge set up?
  A)
  \[97.5\text{ }\Omega \]                           done clear
  B)
  \[105\text{ }\Omega \] done clear
  C)
  \[150\text{ }\Omega \]                            done clear
  D)
  \[110\text{ }\Omega \] done clear
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• question_answer98)
  A potentiometer can measure emf of a cell because:                                                            (CBSE 2020)
  A)
  the sensitivity of potentiometer is large done clear
  B)
  no current is drawn from the cell at balance done clear
  C)
  no current flows in the wire of potentiometer at balance done clear
  D)
  internal resistance of cell is neglected done clear
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• question_answer99)
  For measurement of potential difference, a potentiometer is preferred over voltmeter because:          
  A)
  potentiometer is more sensitive than voltmeter         done clear
  B)
  the resistance of potentiometer is less than voltmeter done clear
  C)
  potentiometer is cheaper than voltmeter done clear
  D)
  potentiometer does not take current from the circuit done clear
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• question_answer100)
  With a certain cell, the balance point is obtained at 65 cm from the end of a potentiometer wire. With another cell whose emf differs from that of the first by 0.1 V, the balance point is obtained at 60 cm. Then the emf of each cell is:
  A)
  1.2 V and 1.5 V respectively done clear
  B)
  2.1 V and 2.2 V respectively done clear
  C)
  1.3 V and 1.2 V respectively done clear
  D)
  5.1 V and 5.2 V respectively done clear
  View Solution play_arrow

• question_answer101)
  Two cells of emfs approximately 5 V and 10 V are to be accurately compared using a potentiometer of length 400cm.                  (NCERT EXEMPLAR)
  A)
  The battery that runs the potentiometer should have voltage of 8 V                                         done clear
  B)
  The battery of potentiometer can have a voltage of 15 V and R adjusted so that the potential drop across the wire slightly exceeds 10V done clear
  C)
  The first portion of 50 cm of wire itself should have potential drop of 10 V done clear
  D)
  Potentiometer is usually used for comparing resistances and not voltages done clear
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• question_answer102)
    AB is a wire of potentiometer with the increase in the value of resistance R, the shift in the balance point J will be:   
  A)
  towards B               done clear
  B)
  towards A               done clear
  C)
  remains constant     done clear
  D)
  first towards B, then back towards A                 done clear
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• question_answer103)
  In a potentiometer a cell of emf 1.5 V gives a balanced point at 32 cm length of the wire. If the cell is replaced by another cell, then the balance point shifts to 65.0 cm, then the emf of second cell is:
  A)
  3.05 V                           done clear
  B)
  2.05 V done clear
  C)
  4.05 V                           done clear
  D)
  6.05 V done clear
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• question_answer104)
  For a cell of emf 2 V, a balance is obtained for 50 cm of the potentiometer wire. If the cell is shunted by a \[2\,\Omega \] resistor and the balance is obtained across 40 cm of the wire, then the internal resistance of the cell is:                    
  A)
  \[1\,\Omega \]                            done clear
  B)
  \[0.5\,\Omega \] done clear
  C)
  \[1.2\,\Omega \]              done clear
  D)
  \[2.5\,\Omega \] done clear
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• question_answer105)
  In a potentiometer the balancing with a cell is at length of 220 cm. On shunting the cell with a resistance of \[3\,\Omega \] balance length becomes 130 cm. What is the internal resistance of this cell?                              
  A)
  \[4.5\,\Omega \]              done clear
  B)
  \[7.8\,\Omega \] done clear
  C)
  \[6.3\,\Omega \]              done clear
  D)
  \[2.08\,\Omega \] done clear
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