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A straight horizontal rod of mass 30 gra...

A straight horizontal rod of mass 30 grams and length 0.3m is placed in a uniform horizontal magnetic field of strength 0.2 T perpendicular to the rod. Calculate the current through the rod, if the force on it just balances its weight. `g=9.8ms^(-2).`

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Verified by Experts

The force acting on the rod is given by `F=BIL`. This force is balances the weight of the rod
`" "BIL=mg`
`therefore " "I=(mg)/(BL)`
`" "I=(30 times 10^(-3) times 9.8)/(0.2 times 0.3)=4.9A.`
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