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A point charge Q(=3xx10^(-12)C) rotates ...

A point charge `Q(=3xx10^(-12)C)` rotates uniformly in a vertical circle of radius R =1 mm. The axis of the circle is aligned along the magnetic axis of the earth. At what value of the angular speed `omega`, the effective magnetic field at the center of the circle will be reduced to zero ? (Horizontal component of Earth's magnetic field is 30 micro Tesla)

A

`10^(11)` rad/s

B

`10^(9)` rad/s

C

`10^(13)` rad/s

D

`10^(7)` rad/s

Text Solution

Verified by Experts

The correct Answer is:
A
`(mu_(0))/(2R) ((omega q)/(2pi )) = 30 xx 10^(-6)`
So `omega = 10^(11)` rad/s
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