Question

The absolute Electric potential at a point distance 20cm from a charge of 2 micro coulomb is

(A) 9 x 10 2 V
(B) 9 x 10 3V
(C) 9 x 10 4 V
(D) 9 x 10 5V
​

Answer 1

Answer:

It's equal to 14πϵo where ϵo is the permitivity of free space =8,85×10−12C2Nm2 . Please always change everything to meters and Coulombs to avoid difficulties with the units.

Answer 2

Answer:

Answer

Correct option is

C

300V

Given : r=9 cm =0.09 m

Charge Q=3 nC =3×10

−9

C

Potential at a distance 9 cm, V=

r

kQ

where k=9×10

9

∴ V=

0.09

9×10

9

×3×10

−9

=300 V