Question

derive an expression for electric field due to uniformly charged circular disc having surface charge density and a point on the axis of the disc​

Answer 1

Answer:

4x=

4

9R

2

+4R

2

x=

2

5

R

Elongation in spring =

2

5

R−2R=

2

1

R

(a) Work done = potential energy

2

1

Kx

2

=

2

1

R

4mg

(

2

1

R)

2

=

2

mgR

(b) initial potential energy = mg

2

3R

using work- energy theorem:

2

1

mv

2

=mgdfrac3R2+

2

1

mgR

v

2

=

4gR

v=2

gR