Question

A proton and an electron enter into a uniform magnetic field with same velocity, then

• A. Forces and accelerations acting on them will be equal in magnitude
• B. Forces and accelerations acting on them will be equal in magnitude as well as direction
• C. Forces acting on them will be equal in magnitude but accelerations are different
• D. Accelerations acting on them are equal tin magnitude but forces are different

Answer 1

The correct option is C Forces acting on them will be equal in magnitude but accelerations are different

Given : $v$ of both are same.

$B$ is uniform

Solution :

We know that magnetic force is given by : $F=q(v\times B)$

Also, $|q_e|=|q_p|$

Therefore $|F_e|=|F_p|$

Hence the magnitude of forces acting on them are equal.

Also, $m_p=1.67\times {10}^{-27}$ and $m_e=9.12\times {10}^{-31}$

Therefore accelerations are different $(\because \text{F = ma})$

Correct Opt: C