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An equilateral triangle frame PQR of mas...

An equilateral triangle frame `PQR` of mass `M` and side a is kept under the influence of magnetic force due to inward perpendicular masgnetic fidl `B` and gravitational field as shownin the figure. Te magnitude and direction of current in the frame so that the frame remains at rest is

A

`I=(2Mg)/aB` , anti clockwise

B

`I=(2Mg)/(aB), clockwise`

C

`I=(Mg)/(aB), anticlockwise`

D

`I=(Mg)/(aB), clockwise`

Text Solution

Verified by Experts

The correct Answer is:
B
`F_(MNPQ)= F_(MQ)` and this force should be upwards to balance the weight.

`:. ilB=mg`, where
`l=MQ=a/2`
`:. i(a/2)B=mg or i=(2Mg)/(aB)`
force is upwards if current is clockwise or current in `MQ` is towards right.
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