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A uniform conducting ring of mass pi kg ...

A uniform conducting ring of mass `pi` kg and radius 1 m is kept on smooth horizontal table. A uniform but time varying magnetic field `B = (hat (i) + t^(2) hat (j))T` is present in the region, where t is time in seconds. Resistance of ring is `2 (Omega)`. Then

Time (in second) at which ring start toppling is

A

`10/(pi)sec`

B

`20/(pi)sec`

C

`5/(pi)sec`

D

`25/(pi)sec`

Text Solution

Verified by Experts

The correct Answer is:
A
`1=1/R |(dphi)/(dt)|=1/2pixx1^(2): 2t=pit`
The ring will start toppling when
`tau_(m)=tau_(g)`
`impliesIAB_(x)=mgr`
`impliespitxxpixx1^(2)xx1=pixx10xx1`
`impliest=10/(pi)`sec
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