CGPET 2021 Solved Paper

As given in problem, an electron is moving in the direction of magnetic field (B).
Hence, θ=0°
The expression of force is
F=qvBsinθ .........(i)
Since, v parallel to B,i.eθ−0°
Therefore, sinθ−sun0°=0
From eq. (i), we get
F=qvB(0)⇒F=0