Question

A charge +q is projected with a velocity $\overrightarrow{v}$ in a magnetic field of induction $\overrightarrow{B}$. The force acting on the charge will be maximum, when the angle between the directions $\overrightarrow{v}$ and $\overrightarrow{B}$ is

• A. $0^o$
• B. ${30}^o$
• C. ${90}^o$
• D. ${45}^o$

Answer 1

Answer: (C)

${90}^o$

Given: charge=q, velocity =v , magnetic field=B, Force =max

Solution: We clearly know the formula of force experienced by a moving charge in magnetic field :

$F=q(v\times B)$

$F=qvBsin\theta$

ATQ force experienced by charge is maximum when $sin\theta$ has it's maximum value .

maximum value of $sin\theta$ is 1 when $sin\theta ={90}^0$

Hence the correct option is C