Question

Two particles of masses $m$ and $2m$ with charges $q$ and $2q$ are placed in a uniform electric field and allowed to move for same time interval. The ratio of their kinetic energies is:

• A. $1:2$
• B. $8:1$
• C. $4:1$
• D. $1:4$

Answer 1

The correct option is A $1:2$

Two particles of mass $=m$ and $2m$

charge $=q$ and $2q$

$\frac{E_1}{E_2}=\frac{q}{2q}=\frac{1}{2}E=qV$

or, $E_1:E_2=1:2$ Kinetic energy $=$ charge $\times$ voltage.