A disc of radius R rotates with constant angular velocity `omega` about its own axis. Surface charge density of this disc varies as `sigma = alphar^(2)`, where r is the distance from the centre of disc. Determine the magnetic field intensity at the centre of disc.

A heavy disc is rotating with uniform angular velocity omega about its own axis. A piece of wax sticks to it. The angular velocity of the disc will

A non-conducting thin disc of radius R rotates about its axis with an angular velocity omega . The surface charge density on the disc varies with the distance r from the centre as sigma(r)=sigma_(0)[1+((r)/(R))^(beta)] , where sigma_(0) and beta are constants. If the magnetic induction at the center is B=((9)/(10))mu_(0)sigma_(0)omegaR , the value of beta is

In a Faraday disc dynamo, a metal disc of radius R rotates with an angular velocity about an axis perpendicular to the plane of the disc and passing through its centre.The disc is placed in a magnetic field B acting perpendicular to the plane of the disc.Determine the induced emf between the rim and the axis of the disc.

A metal disc of radius R rotates with an angular velcoity omega about an axis perpendicular to its plane passing through its centre in a magnetic field B acting perpendicular to the plane of the disc. Calculate the induced emf between the rim and the axis of the disc.

A metal disc of radius R rotates with an angular velcoity omega about an axis perpendiclar to its plane passing through its centre in a magnetic field B acting perpendicular to the plane of the disc. Calculate the induced emf between the rim and the axis of the disc.

A disc of radius R rotates at an angular velocity omega about the axis perpendicular to its surface and passing through its centre. If the disc has a uniform surface charge density sigma , find the magnetic induction on the axis of rotation at a distance x from the centre. (Given R=3m , x=4m and mu_(0)sigmaomega=20Tesla//m .)

A conducting disc of radius r rotaes with a small but constant angular velocity omega about its axis. A uniform magnetic field B exists parallel to the axis of rotation. Find the motional emf between the centre and the periphery of the disc.