A uniform electric field and a uniform magnetic field are produced, pointing in the direction. If an electron is projected with its velocity pointing in the same direction _____

Options

A. The electron will turn to its right.
B. The electron will turn to its left.
C. The electron velocity will increase in magnitude.
D. The electron velocity will decrease in magnitude.

Answer

D

Explanation

As shown in figure, the magnetic force acting on an electron moving parallel with the magnetic field will be zero. So, electric force according to `vecF_(e)=-vecE_(e)` will act on electron in the direction opposite to its motion. As a result of which the velocity of electron will decrease.