Question

Problem 1.04. Two equal charges placed in air and
separated by a distance of 2 m repel each other with a force
of 104 kgf. Calculate the magnitude of either of the charges.
(DSSCC 2006​

Answer 1

Let each charge be q.

Using Coulomb's Law,

F=

4πε

0

1

r

2

q

2

Here, r=2m

F=10

−4

×9.8N

=10

−4

×10N

q

2

=F×4πε

0

×r

2

=10

−4

×

9×10

9

10×1

×(2)

2

=

9

10

−12

×(2)

2

So, q=

3

2

×10

−6

=0.66μC

Each charge is 0.66μC