JEE PYQ: Electrostatics Question 33
Question 33 - 2020 (08 Jan Shift 2)
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):
(1) $v$ vs $x$: saturating curve
(2) $v$ vs $x$: square root curve ($v \propto \sqrt{x}$)
(3) $v$ vs $x$: linear
(4) $v$ vs $x$: parabolic
Show Answer
Answer: (2)
Solution
$v^2 = 2ax = \frac{2qE}{m}x$, so $v = \sqrt{\frac{2qE}{m}}\sqrt{x}$. This is a square root dependence, matching graph (2).
BETA
