Class Xii Physics Physical World And Measurement Mcqs Difficulty Wise

Class 12 Physics Electric Charges and Fields MCQs (Difficulty-wise) with Answers

Use this difficulty-wise set to revise Electric Charges and Fields step-by-step. Start with definitions (charge, conductors/insulators), then move to superposition and dipoles, and finally practise higher-level ideas like dipole field variation and continuous charge distributions. Each question has a short explanation so you can correct mistakes quickly.

Easy (Level 1)

Question 1

Quantisation of charge means:

A. Charge can take any fractional value

B. Charge on a body is an integral multiple of $e$

C. Charge exists only on conductors

D. Charge is always positive

Correct Answer: B

Explanation: $q = ne$, where $n$ is an integer and $e$ is the elementary charge.

Question 2

In the gold-leaf electroscope, divergence of leaves mainly shows:

A. Presence of charge (and roughly how much)

B. Temperature of the body

C. Pressure of surrounding air

D. Mass of the body

Correct Answer: A

Explanation: Like charges on the leaves repel and the separation increases with more charge.

Question 3

Why does a metal spoon usually not remain charged when you try to charge it by rubbing?

A. Metal is an insulator

B. Charge leaks through your body to earth because metal is a conductor

C. Metals cannot have electrons

D. Rubbing creates no charge transfer

Correct Answer: B

Explanation: Conductors allow charge to move easily, so it quickly flows away unless insulated from earth.

Medium (Level 2)

Revision Tip: For direction-based questions, mark: (1) direction of electric field is for a positive test charge, (2) field lines never intersect.

Question 4

Assertion (A): Electric field lines around a positive point charge point radially outward. Reason (R): The electric field at any point is along the tangent to the field line at that point.

A. Both A and R are true and R is the correct explanation of A

B. Both A and R are true but R is not the correct explanation of A

C. A is true but R is false

D. A is false but R is true

Correct Answer: A

Explanation: Field lines show direction of $\vec{E}$; outward for a positive charge.

Question 5

An electric dipole has charges $+q$ and $-q$ separated by $2a$. The dipole moment vector $\vec{p}$ is directed:

A. From $+q$ to $-q$

B. From $-q$ to $+q$

C. Perpendicular to the line joining the charges

D. In random direction

Correct Answer: B

Explanation: By convention, $\vec{p}$ points from negative to positive charge.

Question 6

A dipole is placed in a uniform electric field. Which statement is correct?

A. Net force is zero and torque is zero

B. Net force is non-zero but torque is zero

C. Net force is zero but torque tends to align $\vec{p}$ with $\vec{E}$

D. Both net force and torque are always non-zero

Correct Answer: C

Explanation: Equal and opposite forces act on the charges (net force zero), but they form a couple that produces torque.

Hard (Level 3)

Revision Tip: When a question says “continuous distribution”, think “integrate small pieces” and use superposition.

Question 7

At large distances $r$ ($r \gg 2a$) from an electric dipole, the electric field magnitude varies as:

A. $\frac{1}{r}$

B. $\frac{1}{r^2}$

C. $\frac{1}{r^3}$

D. Constant

Correct Answer: C

Explanation: Dipole field falls faster than a point charge field: $E_{\text{dipole}} \propto \frac{1}{r^3}$.

Question 8

Electric field due to a continuous charge distribution can be found by:

A. Ignoring Coulomb’s law

B. Adding contributions of small charge elements and integrating

C. Using only total charge irrespective of distribution

D. Using only the nearest charge element

Correct Answer: B

Explanation: Break the distribution into small elements $dq$ and add $d\vec{E}$ using superposition.

Question 9

The fundamental reason bodies get charged on rubbing is:

A. Creation of new charges

B. Transfer of electrons

C. Transfer of protons

D. Destruction of atoms

Correct Answer: B

Explanation: Electrons can transfer between materials; charges are not created or destroyed.

Question 10

The solid angle $d\Omega$ subtended by area element $dS$ at distance $r$ from a point is:

A. $d\Omega = dS,r^2$

B. $d\Omega = \frac{dS}{r^2}$

C. $d\Omega = \frac{r}{dS}$

D. $d\Omega = dS,r$

Correct Answer: B

Explanation: $d\Omega = \frac{dS}{r^2}$.

Want a mixed set for quick revision? Go back to: Class 12 Physics Electric Charges and Fields MCQs (Mixed).

If you’re short on time, do Easy + Medium first, then attempt only 2–3 Hard questions and revise the explanations.