Current Electricity is a crucial chapter in Class 12 Physics, forming the foundation for understanding electric circuits, resistivity, and Ohm’s law. Questions from this topic are frequently asked in board exams, JEE, NEET, and other entrance tests.
Here we’ve compiled 75 important objective questions with options and one-word answers that cover every key concept in this chapter. Practice these regularly to strengthen your concepts and score higher in exams.
Class 12 Current Electricity Objective Questions with Answers | 75 Physics MCQs
Objective Questions-Class 12 Current Electricity Objective Questions
Q1. The SI unit of electric current is:
a) Ohm
b) Ampere
c) Coulomb
d) Volt
Answer: Ampere
Q2. Ohm’s Law is represented as:
a) V = IR
b) V = I/R
c) V = R/I
d) I = VR
Answer: V = IR
Q3. The reciprocal of resistance is known as:
a) Capacitance
b) Inductance
c) Conductance
d) Reluctance
Answer: Conductance
Q4. Drift velocity of electrons is:
a) Very large
b) Zero
c) Very small
d) Infinite
Answer: Very small
Q5. 1 coulomb of charge equals:
a) 1 electron
b) 6.25×10186.25 \times 10^{18} electrons
c) 1.6×10−191.6 \times 10^{-19} electrons
d) None
Answer: 6.25×10186.25 \times 10^{18} electrons
Q6. Resistance of a wire depends on:
a) Length
b) Area
c) Material
d) All of these
Answer: All of these
Q7. The resistivity of a conductor depends on:
a) Length
b) Temperature and material
c) Area
d) Shape
Answer: Temperature and material
Q8. Kirchhoff’s first law is based on:
a) Conservation of energy
b) Conservation of charge
c) Conservation of current
d) Conservation of mass
Answer: Conservation of charge
Q9. Kirchhoff’s second law is based on:
a) Conservation of mass
b) Conservation of energy
c) Conservation of charge
d) Conservation of momentum
Answer: Conservation of energy
Q10. The resistance of an ideal ammeter is:
a) Infinite
b) Zero
c) Very high
d) Constant
Answer: Zero
Q11. The resistance of an ideal voltmeter is:
a) Zero
b) Infinite
c) Very small
d) Constant
Answer: Infinite
Q12. Which device is used to measure potential difference?
a) Ammeter
b) Voltmeter
c) Galvanometer
d) Rheostat
Answer: Voltmeter
Q13. The unit of resistivity is:
a) Ohm
b) Ohm-meter
c) Siemens
d) Volt
Answer: Ohm-meter
Q14. EMF stands for:
a) Electric magnetic field
b) Electromotive force
c) Electron magnetic flux
d) None
Answer: Electromotive force
Q15. Drift velocity is directly proportional to:
a) Current
b) Electric field
c) Voltage
d) Resistance
Answer: Electric field
Q16. Ohm’s law fails for:
a) Metals
b) Semiconductors
c) Electrolytes
d) Both b and c
Answer: Both b and c
Q17. The slope of a V-I graph gives:
a) Conductance
b) Resistance
c) Power
d) Capacitance
Answer: Resistance
Q18. Resistivity of a metal increases with:
a) Increase in temperature
b) Decrease in temperature
c) Constant temperature
d) Pressure
Answer: Increase in temperature
Q19. Superconductors have:
a) Zero resistivity
b) Infinite resistance
c) Constant resistance
d) High resistivity
Answer: Zero resistivity
Q20. The current in a circuit is given by:
a) I=VRI = \frac{V}{R}
b) I=VRI = VR
c) I=R/VI = R/V
d) I=V2RI = V^2R
Answer: I=VRI = \frac{V}{R}
Q21. The SI unit of power is:
a) Joule
b) Watt
c) Volt
d) Ampere
Answer: Watt
Q22. The drift velocity is measured in:
a) m/s
b) cm/s
c) m²/s
d) J/s
Answer: m/s
Q23. The current due to flow of electrons is called:
a) Conventional current
b) Electronic current
c) Ionic current
d) Positive current
Answer: Electronic current
Q24. The relation between current and drift velocity is:
a) I=neAvdI = neAv_d
b) I=nAvdI = nAv_d
c) I=eAvdI = eAv_d
d) I=ne/vdI = ne/v_d
Answer: I=neAvdI = neAv_d
Q25. In metals, current is due to:
a) Electrons
b) Protons
c) Neutrons
d) Ions
Answer: Electrons
Q26. The resistance of a wire increases when:
a) Length increases
b) Area increases
c) Temperature decreases
d) All
Answer: Length increases
Q27. Conductivity is reciprocal of:
a) Resistance
b) Resistivity
c) Voltage
d) Power
Answer: Resistivity
Q28. The unit of conductivity is:
a) Ohm
b) Ohm⁻¹m⁻¹
c) Ohm-meter
d) Ampere
Answer: Ohm⁻¹m⁻¹
Q29. A rheostat is used to:
a) Measure voltage
b) Vary resistance
c) Measure current
d) Store charge
Answer: Vary resistance
Q30. The internal resistance of a cell depends on:
a) Nature of electrolyte
b) Distance between electrodes
c) Temperature
d) All of these
Answer: All of these
Q31. Current is scalar or vector?
a) Scalar
b) Vector
c) Tensor
d) None
Answer: Scalar
Q32. The potential difference between two points is 1 volt when 1 coulomb of charge does how much work?
a) 1 joule
b) 1 watt
c) 1 newton
d) 1 ampere
Answer: 1 joule
Q33. The symbol for resistance is:
a) R
b) V
c) I
d) P
Answer: R
Q34. A voltmeter is always connected:
a) In series
b) In parallel
c) Both
d) None
Answer: In parallel
Q35. An ammeter is always connected:
a) In series
b) In parallel
c) Both
d) None
Answer: In series
Q36. If potential difference doubles, current will:
a) Halve
b) Double
c) Become zero
d) Remain same
Answer: Double
Q37. The heating effect of current is given by:
a) H=I2RtH = I^2Rt
b) H=IRtH = IRt
c) H=VItH = VIt
d) Both a and c
Answer: H=I2RtH = I^2Rt
Q38. Unit of electric charge:
a) Coulomb
b) Ampere
c) Volt
d) Ohm
Answer: Coulomb
Q39. The direction of conventional current is:
a) Same as electron flow
b) Opposite to electron flow
c) Random
d) Perpendicular
Answer: Opposite to electron flow
Q40. In series combination, total resistance is:
a) R=R1+R2+R3R = R_1 + R_2 + R_3
b) 1/R=1/R1+1/R21/R = 1/R_1 + 1/R_2
c) R=R1R2R = R_1R_2
d) None
Answer: R=R1+R2+R3R = R_1 + R_2 + R_3
Q41. In parallel combination, total resistance is:
a) 1/R=1/R1+1/R2+1/R31/R = 1/R_1 + 1/R_2 + 1/R_3
b) R=R1+R2+R3R = R_1 + R_2 + R_3
c) R=R1R2R3R = R_1R_2R_3
d) None
Answer: 1/R=1/R1+1/R2+1/R31/R = 1/R_1 + 1/R_2 + 1/R_3
Q42. A material with low resistivity is:
a) Conductor
b) Insulator
c) Semiconductor
d) Dielectric
Answer: Conductor
Q43. A material with high resistivity is:
a) Conductor
b) Insulator
c) Semiconductor
d) Superconductor
Answer: Insulator
Q44. Resistivity of a conductor at 0 K is:
a) Infinite
b) Zero
c) Constant
d) Negative
Answer: Zero
Q45. For a constant current, when resistance increases, voltage must:
a) Increase
b) Decrease
c) Remain constant
d) None
Answer: Increase
Q46. The SI unit of resistance is:
a) Ohm
b) Volt
c) Watt
d) Ampere
Answer: Ohm
Q47. The current in a metallic conductor is due to:
a) Flow of electrons
b) Flow of protons
c) Both
d) None
Answer: Flow of electrons
Q48. The instrument used to detect current is:
a) Ammeter
b) Voltmeter
c) Galvanometer
d) Wattmeter
Answer: Galvanometer
Q49. The drift speed of electrons is about:
a) 10⁶ m/s
b) 10⁻⁴ m/s
c) 10⁴ m/s
d) 10² m/s
Answer: 10⁻⁴ m/s
Q50. Current density (J) is given by:
a) J=I/AJ = I/A
b) J=A/IJ = A/I
c) J=IRJ = IR
d) J=V/AJ = V/A
Answer: J=I/AJ = I/A
Q51. The unit of current density is:
a) A/m²
b) A/m
c) A/cm²
d) V/m
Answer: A/m²
Q52. The formula for resistivity is:
a) ρ=RA/L\rho = RA/L
b) ρ=RL/A\rho = RL/A
c) ρ=L/RA\rho = L/RA
d) ρ=1/RA\rho = 1/RA
Answer: ρ=RA/L\rho = RA/L
Q53. If length is doubled and area halved, resistance becomes:
a) 2R
b) 4R
c) R/2
d) R/4
Answer: 4R
Q54. The slope of the I–V graph represents:
a) Conductance
b) Resistance
c) Power
d) None
Answer: Conductance
Q55. The emf of a cell is measured in:
a) Volt
b) Ampere
c) Ohm
d) Watt
Answer: Volt
Q56. If a current of 2A flows for 5s, total charge = ?
a) 2C
b) 5C
c) 10C
d) 0.4C
Answer: 10C
Q57. The potential difference across a resistor of 10Ω carrying 2A current is:
a) 5V
b) 10V
c) 15V
d) 20V
Answer: 20V
Q58. Which of the following obeys Ohm’s law?
a) Copper wire
b) Diode
c) Thermistor
d) Vacuum tube
Answer: Copper wire
Q59. The SI unit of charge is:
a) Coulomb
b) Ampere
c) Volt
d) Joule
Answer: Coulomb
Q60. A fuse wire is made of:
a) High resistance material
b) Low resistance material
c) Insulator
d) Magnetic material
Answer: High resistance material
Q61. Power consumed by a resistor is:
a) P=VIP = VI
b) P=I2RP = I^2R
c) P=V2/RP = V^2/R
d) All of these
Answer: All of these
Q62. The color code for a 10Ω resistor with ±5% tolerance is:
a) Brown-Black-Black-Gold
b) Red-Black-Brown
c) Brown-Black-Brown-Gold
d) Red-Red-Black
Answer: Brown-Black-Black-Gold
Q63. In a series circuit, current:
a) Increases
b) Decreases
c) Remains same
d) Becomes zero
Answer: Remains same
Q64. In a parallel circuit, voltage:
a) Same across each branch
b) Different
c) Depends on current
d) None
Answer: Same across each branch
Q65. The heating element of electric iron is made of:
a) Copper
b) Tungsten
c) Nichrome
d) Silver
Answer: Nichrome
Q66. The internal resistance of a cell is usually:
a) High
b) Low
c) Infinite
d) Zero
Answer: Low
Q67. A cell converts:
a) Mechanical energy to electrical energy
b) Chemical energy to electrical energy
c) Electrical energy to heat
d) None
Answer: Chemical energy to electrical energy
Q68. EMF of a cell depends on:
a) Nature of electrodes
b) Nature of electrolyte
c) Temperature
d) All of these
Answer: All of these
Q69. The SI unit of electric field is:
a) N/C
b) V/m
c) Both a and b
d) A/m
Answer: Both a and b
Q70. A galvanometer can be converted into ammeter by:
a) Adding high resistance in series
b) Adding low resistance in parallel
c) Removing resistance
d) None
Answer: Adding low resistance in parallel
Q71. A galvanometer can be converted into voltmeter by:
a) Adding high resistance in series
b) Adding low resistance in series
c) Adding low resistance in parallel
d) None
Answer: Adding high resistance in series
Q72. Wheatstone bridge is used to measure:
a) Resistance
b) Voltage
c) Current
d) EMF
Answer: Resistance
Q73. The null point in a potentiometer means:
a) Zero resistance
b) No current flows through galvanometer
c) Maximum current
d) Infinite resistance
Answer: No current flows through galvanometer
Q74. The sensitivity of potentiometer increases with:
a) Increasing length
b) Decreasing current
c) Both
d) None
Answer: Both
Q75. The SI unit of potential difference is:
a) Volt
b) Joule
c) Watt
d) Ampere
Answer: Volt
Conclusion-Class 12 Current Electricity Objective Questions
These 75 Class 12 Current Electricity Objective Questions with options and one-word answers will help you test your conceptual clarity and preparation level. Make sure to practice these regularly, revise your NCERT concepts, and apply them to numerical problems for better results in both board and competitive exams.
FAQs-Class 12 Current Electricity Objective Questions
Q1. What are the most important topics in Class 12 Current Electricity?
Answer: The most important topics include Ohm’s Law, Kirchhoff’s Laws, resistivity, drift velocity, combination of resistors (series and parallel), EMF, internal resistance, and Wheatstone Bridge.
Q2. How many marks does Current Electricity carry in Class 12 board exams?
Answer: Current Electricity generally carries 6–8 marks in the CBSE Class 12 Physics Board Exam, depending on the question paper pattern.
Q3. What is the formula of Ohm’s Law?
Answer: Ohm’s Law is given by the formula V = IR, where V is potential difference, I is current, and R is resistance.
Q4. What is the difference between EMF and potential difference?
Answer:
-
EMF (Electromotive Force): It is the total energy supplied per unit charge by a source when no current flows.
-
Potential Difference: It is the energy used per unit charge between two points when current flows.
Q5. How can I prepare Current Electricity for JEE and NEET?
Answer:
-
Revise NCERT theory thoroughly.
-
Practice numerical problems and objective questions daily.
-
Understand concepts like drift velocity, resistivity, and Kirchhoff’s laws deeply.
-
Attempt mock tests and previous year papers regularly.
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