Question

The mass of electron moving with velocity of light is? A) 2×mass of electron B) 3×mass of electron C) infinite D) zero

Answer 1

Hendrik Lorentz had formulated effective mass for moving particles.

    $\gamma = \frac{1}{\sqrt{1-\frac{v^2}{c^2}}}, c=speed\ of\ light\\\\Mass_L = m_L = \gamma^3*m,,\ \ \ m=rest\ mass\ when\ velocity\ v\ is\ 0.\\\\No\ particle\ can\ go\ beyond\ speed\ of\ light.\\\\mass (longitudinal)\ when\ v=c/2,\ is=\frac{8m}{3\sqrt{3}}\\\\mass\ when\ v=\frac{99*c}{100},\ is=1000*m\\\\mass\ when\ v=c=velocity\ of\ light,\ is=\infty$

These are derived from theory of relativity.

Answer 2

Answer is

(C)

Infinite