12) is it b)?????
1) A thin insulating rod is charged in a uniform manner & the resulting linear charge density is λ.
The rod is bent into the shape of a semi-circle.
Find the magnitude of the electric field strength at the centre.
2) A Gold Leaf Electroscope is charged & leaves are observed to diverge by a certain amount.
A beam of X-rays is allowed to fall upon the electrosope for a short period.
The effect is as follows ::
a) Leaves diverge further.
b) Leaves will collapse.
c) No change in the divergence of leaves.
d) Gold leaves will melt.
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8 Answers
131) They have given the ans - λ/2πεR....Kaise?
2) Answer's b).... Mona, how ?
106dq = λRdθ
∫dE = ∫14πελRdθ/R2sinθ
= λ4πεR [cosθ] (pi to 0)
= λ/2πεR
106definitely..
as @ = sin@ only if @-->0
whereas here @ varies from 0 to pi which is not --> 0