Question

A loop of radius r carries a uniformly charge.Assuming the potential at infinity to be zero,the ratio of the potential at a height 2r on the axis to that at a height 3r.

Answer 1

Answer:

Electric field strength along the x-axis due to charged ring is E=kQ

(x

2

+R

2

)

3

x

where k=

4πϵ

0

1

For x=R, E

1

=kQ

(R

2

+R

2

)

3

R

=kQ

2

2

R

2

1

for x=

2

R

,E

2

=kQ

(

2

R

2

+R

2

)

3

2

R

=kQ

3

3

R

2

2

∴

E

2

E

1

=

2

2

R

2

1

×

2

3

3

R

2

=

4

2

3

3