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A thin, 50 cm long metal bar with mass 7...

A thin, 50 cm long metal bar with mass 750 g rests on, but is not attrached to, two metallic supports in a uniform 0.450T magnetic field, as shown in fig. A battery and a `25Omega` resistor in series are connected to the supports.

What is the largest voltage the battery can have without breaking the circuit at the supports?

A

817

B

718

C

827

D

837

Text Solution

Verified by Experts

The correct Answer is:
1
As `F-mg` when the bar is just ready to levitate,
`IIB=mg or I=(mg)/(lB)=(0.750xx9.8)/(0.5xx0.45)A=32.67A`
`epsilon=IR=(32.67)(25)V=817V`
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