Question

When a charged particle enters in a uniform magnetic field, then its kinetic energy

• A. remains constant
• B. increases
• C. decreases
• D. becomes zero

Answer 1

The correct option is A remains constant

When a charged particle enters a magnetic field $B$ its kinetic energy remains constant as the force exerted on the particle is:
$F=q\overrightarrow{V}\times \overrightarrow{B}$
is perpendicular to $\overrightarrow{V}$, so the work done by $\overrightarrow{B}=0$. This does not cause any change in kinetic energy.