Question:
A particle of mass $m$ and charge $q$ is released from rest in a uniform electric field. If there is no other force on the particle, the dependence of its speed $v$ on the distance $x$ travelled by it is correctly given by (graphs are schematic and not drawn to scale)
Correct Option: , 2
Solution:
Using
$v^{2}-u^{2}=2 a S$ ...(1)
Here, $u=0, s=x$
Also, $F_{\text {electric }}=m a$
Substituting the values in (i) we get
$v^{2}=\frac{2 q E}{m} \cdot x$
$\Rightarrow q E=m a$
$\Rightarrow a=\frac{q E}{m}$