Question

A conducting sphere of radius 5 cm has a charge of 31-41 MC. Calculate the
surface density of charge.​

Answer 1

Answer:

Electric field intensity (E) at a distance (d) from the centre of a sphere containing net charge q is given by the relation,

E=

4π∈

0

d

2

q

Where,

q= Net charge = 1.5×5

3

N/C

d= =20cm=0.2m

And,

4π∈

0

1

=9×5

9

Nm

2

C

−2

∴q=E(4π∈

0

)d

2

=

9×10

9

1.5×5

3

×(0.2)

2

=6.67×10

9

C

=6.67nC.

Because the electric field lines point radially inwards, the charge on the sphere is negative. Therefore, the net charge on the sphere is 6.67 nC.