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What charge would be required to electri...

What charge would be required to electrify a sphere of radius 25 cm, so as to get a surface charge density of `3/pi C/m^2`?

A

0.25

B

0.75 C

C

0.57C

D

0.5C

Text Solution

Verified by Experts

The correct Answer is:
B
`sigma=Q/A=Q/(4 pir^2)`
`therefore Q=4pi R^2sigma=4 times pi times (25 times 10^-2)^2 times 3/pi`
`=4 times 625 times 10^-4 times 3`
`=7500 times 10^-4=0.75C`
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