Doublyionized helium atoms and hydrogen ions are accelerated, from rest, through the same potential difference. Find the ratio of final velocities of helium and hydrogen.

Options

A. `1/sqrt2`
B. `1/2`
C. `sqrt2`
D. 2

Answer

A

Explanation

Kinetic energy = Electric energy
or `1/2 mv^2 =qV " or " v = sqrt((2qV)/m`
Accelerating voltage V is same. `:. (v_(He))/(v_H)= sqrt((q_(He))/(q_H) xx (m_H)/(m_(He))) " or " (v_He)/(v_H) = sqrt((2e)/exxm/(4m))=1/sqrt2 :. (v_(He))/(v_H) =1/sqrt2`