Question

How does the kinetic energy of a charge change as the charge moves under the effect of an electric field from higher potential to lower potential?

A.
The kinetic energy increases.
B.
The kinetic energy decreases.
C.
The kinetic energy remains the same.
D.
The kinetic energy is always zero.

Answer 1

The kinetic energy of a charged particle is related to the electric field potential via the following equation:

1/2*m*v² = q* E -----(1)

where m = mass of the particle

v = velocity

q = charge

E = potential

since kinetic energy KE = 1/2mv², eq (1) can be written as:

KE = q*E

i.e kinetic energy of a charge is directly proportional to the strength of the electric field potential (E)

Therefore, as the charge moves from a higher to a lower potential, its kinetic energy will also decrease.

Ans: B)

The kinetic energy decreases