Question

# A particle of mass m and charge q is released from rest in a uniform electric field E. The kinetic energy attained by the particle after moving a distance x along the electric field is

A

qEx2

No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
B

qE2x

No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
C

qEx

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D

q2Ex

No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
Open in App
Solution

## The correct option is C qEx Initial kinetic energy of the particle is zero. The gain in kinetic energy in distance x = decrease in potential energy = work done by the electric field to move the particle = force on q due to electric field E × distance =qE × x. Hence the correct choice is(c). Or By work energy theorom, the change in kinetic energy of the system is equal to the net work done by all the forces on the system: So, K.Ef−K.Ei = qEx Also, the charge is released from rest, So K.Ei=0 \(\therefore The K.E attained = qEx .

Suggest Corrections
3
Join BYJU'S Learning Program
Related Videos
Potential Energy of a System of Point Charges
PHYSICS
Watch in App
Join BYJU'S Learning Program