Target Exam

CUET

Subject

Physics

Chapter

Moving Charges and Magnetism

Question:

In a magnetic field,

(A) a charged particle in motion can experience a force
(B) a charged particle at rest, experiences a force
(C) there is no change in the speed of the charged particle
(D) there is a change in the kinetic energy of the charged particle.

Choose the correct answer from the options given below:

Options:

(A), (B) and (D) only

(A) and (C) only

(A), (B), and (C) only

(B), (C) and (D) only

Correct Answer:

(A) and (C) only

Explanation:

The correct answer is Option (2) → (A) and (C) only

(A) A charged particle in motion can experience a force — ✔ True (Magnetic force $F = q(\vec{v} \times \vec{B})$, nonzero if velocity has a component perpendicular to $\vec{B}$.)

(B) A charged particle at rest experiences a force — ✖ False (At rest, $\vec{v}=0$ ⇒ $\vec{F}=0$)

(C) There is no change in the speed of the charged particle — ✔ True (Magnetic force acts perpendicular to velocity ⇒ no work done ⇒ speed constant)

(D) There is a change in the kinetic energy of the charged particle — ✖ False (No work done by magnetic force ⇒ kinetic energy constant)

Final Answer:

(A) and (C)