The figure shows three situations when an electron moves with velocity `vec(v)` travels through a uniform magnetic field `vec(B)`. In each case, what is the direction of magnetic force on the electron

Options

A. positive z axis negative x axis positive y axis
B. negative z axis negative x axis and zero
C. positive z axis positive y axis and zero
D. negative z axis positive x axis and zero

Answer

B

Explanation

According to fleming left hand rule in and magnetic force on the electron will be directed in negative Z axis and negative X axis respectively velocity of elctron and direction of magnetic field are anti parallel so no force will act on electron