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A ring rotates with angular velocity ome...

A ring rotates with angular velocity `omega` about an axis perpendicular to the plane of the ring passing through the center of the ring.A constant magnetic field `B` exists parallel to the axis.Find the `emf` induced in the ring.

Text Solution

Verified by Experts

Flux passing through the ring `phi=B.A` is a constant there, therefore `emf` induced in the coil is zero.Every point of the ring is at the same potential, by symmetry.
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Knowledge Check

  • A ring of radius R is made of a thin wire of material of density rho having cross section area a. The ring rotates with angular velocity omega about an axis passing through its centre and perpendicular to the plane. If we consider a small element of the ring,it rotates in a circle. The required centripetal force is provided by the component of tensions on the element towards the centre. A small element of length dl of angular width d theta is shown in the figure. If T is the tension in the ring, then

    A
    `T=(a rho R^(2)omega^(2))/(2)`
    B
    `T=a rho R^(2) omega^(2)`
    C
    `a^(2) rho omega^(2)`
    D
    `T=2arho R^(2) omega^(2)`

  • A conducting ring is placed in a uniform magnetic field with its plane perpendicular to the field . An emf is induced in the ring if

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    B
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    D
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    B
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    C
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    D
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