Question

3 A negative charge of 30 esu is placed at a distance of 30 cm from a positive charge of 20 esu. At what point will the potential between the charges be zero ?
- A.
10 cm away from the first charge
B.
12 cm away from both the charges
C.
O 12 cm away from the first charge
D.
O 12 cm away from the second charge
A beam of light ray falls on a glass slab. What is the velocity of the light, such that when the light falls on the surface at an angle 55°, the reflected ray comes​

Answer 1

Answer:12 cm from 2nd charge

Explanation:

Let at x cm distance from 2nd charge potential is 0.

0= {(20/x)- (30/30-x)}

Or, 3x= 2(30-x)

Or, 3x= 60-2x

Or, 5x= 60

Or, x =12 (ans)