Assertion : When the speed of an electron increases its specific charge decreases.
Reason : Specific charge is the ratio of the change to mass.

Options

A. If both assertion and reason are true and reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not correct explanation of the assertion.
C. If assertion is true but the reason is false.
D. If both the assertion and reason are false.

Answer

B

Explanation

Charge does not change with speed but mass varies with the speed as per relation `m = (m_(0))/(sqrt(( 1 - (v^(2))/(c^(2)))))`.
Hence specific charge `e//m` decreases with increase in speed.