Class 12 Physics MCQ Chapter 3 Current Electricity
Looking for the best Class 12 Physics MCQ Chapter 3 Current Electricity English Medium study material? This article provides a complete collection of important multiple-choice questions (MCQs) with answers, specially prepared for AHSEC Higher Secondary students to strengthen their exam preparation.
Current Electricity is one of the most important chapters in Class 12 Physics, covering fundamental concepts related to electric current and electrical circuits. Students will revise key topics such as electric current, drift velocity, Ohm’s law, resistance, resistivity, conductivity, Kirchhoff’s laws, Wheatstone bridge, potentiometer, and electrical energy. These concepts are frequently tested in board examinations and form the foundation for many advanced topics in Physics.
The MCQs included in this article are based on the latest AHSEC syllabus and examination pattern, making them highly relevant for effective revision and self-assessment. Regular practice of these objective questions will help students improve conceptual clarity, enhance numerical-solving skills, and increase confidence before examinations.
Whether you are preparing for class tests, model exams, or the AHSEC Higher Secondary Final Examination, these Chapter 3 MCQ solutions will help you achieve better results and strengthen your understanding of Current Electricity.
Part: I
Class 12 Physics MCQ Chapter 3 Current Electricity
VSA & MCQ
I. Very Short Answer Questions
Q. What is electric current?
Ans: Electric current is the rate of flow of charge, I = Q / t.
Q. What is the SI unit of current?
Ans: Ampere (A).
Q. Define 1 ampere.
Ans: 1 A = 1 C/s.
Q. What is drift velocity?
Ans: The average velocity of charge carriers in a conductor.
Q. What is current density?
Ans: Current per unit area, J = I / A.
Q. What is Ohm’s law?
Ans: V = IR.
Q. What is resistance?
Ans: Opposition to the flow of current.
Q. What is the SI unit of resistance?
Ans: Ohm (Ω).
Q. Define resistivity.
Ans: ρ = RA / L.
Q. What is conductivity?
Ans: σ = 1 / ρ.
Q. What is mobility?
Ans: μ = v_d / E.
Q. What is relation between current and drift velocity?
Ans: I = nqAv_d.
Q. What is temperature effect on resistance?
Ans: Resistance increases with temperature for metals.
Q. What is relaxation time?
Ans: Average time between collisions of electrons.
Q. What is electric power?
Ans: P = VI.
Q. Write another power formula.
Ans: P = I²R.
Q. Write power in terms of voltage.
Ans: P = V² / R.
Q. What is EMF?
Ans: Energy supplied per unit charge.
Q. What is terminal voltage?
Ans: V = E − Ir.
Q. What is internal resistance?
Ans: Resistance inside a cell.
Q. What is series combination of resistors?
Ans: R = R₁ + R₂ + …
Q. What is parallel combination of resistors?
Ans: 1/R = 1/R₁ + 1/R₂ + …
Q. State Kirchhoff’s current law.
Ans: Sum of currents at a junction is zero.
Q. State Kirchhoff’s voltage law.
Ans: Sum of voltages in a loop is zero.
Q. What is Wheatstone bridge?
Ans: Circuit used to measure unknown resistance.
Q. What is meter bridge?
Ans: Practical form of Wheatstone bridge.
Q. What is potentiometer?
Ans: Device to measure potential difference accurately.
Q. What is balanced condition in bridge?
Ans: No current flows through galvanometer.
Q. What is resistivity unit?
Ans: Ω·m.
Q. What is relation between J and E?
Ans: J = σE.
II. Multiple Choice Questions
Q. Unit of current is:
(a) Volt
(b) Ampere
(c) Ohm
(d) Watt
Ans: (b)
Q. Ohm’s law is:
(a) V = IR
(b) I = VR
(c) R = VI
(d) V = I/R
Ans: (a)
Q. Resistance unit is:
(a) Volt
(b) Ampere
(c) Ohm
(d) Joule
Ans: (c)
Q. Resistivity depends on:
(a) Length
(b) Area
(c) Material
(d) Shape
Ans: (c)
Q. Current density is:
(a) Scalar
(b) Vector
(c) Constant
(d) Zero
Ans: (b)
Q. Drift velocity increases with:
(a) Temperature
(b) Electric field
(c) Resistance
(d) Length
Ans: (b)
Q. Power formula is:
(a) VI
(b) V/I
(c) I/V
(d) IR
Ans: (a)
Q. Series resistance:
(a) Increases
(b) Decreases
(c) Same
(d) Zero
Ans: (a)
Q. Parallel resistance:
(a) Increases
(b) Decreases
(c) Same
(d) Infinite
Ans: (b)
Q. Kirchhoff law is based on:
(a) Charge conservation
(b) Energy conservation
(c) Both
(d) None
Ans: (c)
Q. Assertion: Current is scalar. Reason: It has only magnitude.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: Resistance increases with temperature. Reason: Collisions increase.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: J = σE. Reason: Conductivity relates current and field.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: EMF is equal to terminal voltage always. Reason: Internal resistance exists.
(a) Both true
(b) Both false
(c) Assertion true, reason false
(d) Assertion false, reason true
Ans: (d)
Q. Assertion: Wheatstone bridge measures resistance. Reason: Based on null method.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: Power can be zero. Reason: No current flows.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a)
Q. Assertion: Drift velocity is small. Reason: Frequent collisions occur.
(a) Both true, reason correct
(b) Both true, reason incorrect
(c) Assertion true, reason false
(d) Both false
Ans: (a).
