Electric field at 20 ,cm from centre of a uniformly charged non-conducting sphere of radius 10 ,cm i

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1. Electric Charges and Fields

medium

The electric field at $20 \,cm$ from the centre of a uniformly charged non-conducting sphere of radius $10 \,cm$ is $E$. Then at a distance $5 \,cm$ from the centre it will be

A

$16 E$

B

$4 E$

C

$2 E$

D

Zero

Solution

(c)

$R=10 \,cm , \quad r=20 \,cm$

$E=\frac{k Q}{(0.2)^2}$

Now at $r=5 \,cm$

$E^{\prime}=\frac{k Q(0.05)}{(0.1)^3}$

Now, $\frac{E^{\prime}}{E}=\frac{(0.05)}{(0.1)^3}(0.2)^2=2$

$E=2 E$

Standard 12

Physics

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