Target Exam

CUET

Subject

Physics

Chapter

Moving Charges and Magnetism

Question:

A rod AB moves with uniform velocity v in a uniform magnetic field as shown in the figure. Identify the correct statement(s) among the following.

(A) Rod becomes electrically charged.
(B) End A becomes positively charged.
(C) End B becomes positively charged.
(D) Rod becomes hot due to joule's heating.

Choose the correct answer from the options given below:

Options:

(B) only

(A) and (D) only

(B) and (D) only

(C) only

Correct Answer:

(B) only

Explanation:

The correct answer is Option (1) → (B) only

Magnetic field: into the page (×). Velocity: to the right.

Force on positive charges: $\vec{F}=q(\vec{v}\times\vec{B})$ → direction upward (towards A), so positive charges accumulate at A and negative charges at B.

Net charge of the rod remains zero (only charge separation), so statement (A) is false, (B) is true, (C) is false, (D) is false.