ElectrostaticsHard
Question
The linear charge density on a dielectric ring of radius R varies with θ as λ = λ0 cos θ/2, where λ0 is constant. Find the potential at the centre O of ring. [in volt] :-
Options
A.λ0R
B.
C.
D.zero
Solution
The charge on the infinitesimal elements of arc which subtend an angle dθ at the centre of the ring.

dQ = λRd θ = λ0 cos
Rd θ
Potential at the centre of ring due to charge dQ
dV =
V = ∫dV ⇒ V =
=
= 0V

dQ = λRd θ = λ0 cos
Potential at the centre of ring due to charge dQ
dV =
V = ∫dV ⇒ V =
=
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