A gramophone disc of brass of diameter 30 cm rotates horizontally at the rate of `100//3` revolutions per minute. If the vertical component of the earth's magnetic field be `0.01" weber"//"metre"^(2)`, then the emf induced between the centre and the rim of the disc will be-

A bicycle wheel of radius 0.5 m has 32 spokes. It is rotating at the rate of 120 revolutions per minute, perpendicular to the horizontal component of earth's magnetic field B_(H) = 4 xx 10^(–5) tesla. The emf induced between the rim and the centre of the wheel will be-

An aeroplane having a distance of 50 metre between the edges of its wings is flying horizontally with a speed of 360km // hour. If the vertical component of earth’s magnetic field is 4 xx 10^(–4)" weber"//m^(2) , then the induced emf between the edges of its wings will be –

A wheel with 20 metallic spokes each of length 8.0 m long is rotated with a speed of 120 revolution per minute in a plane normal to the horizontal component of earth magnetic field H at a place. If H=0.4xx10^(-4) T at the place, then induced emf between the axle the rim of the wheel is

A wheel with 20 metallic spokes each of length 8.0 m long is rotated with a speed of 120 revolution per minute in a plane normal to the horizontal component of earth magnetic field H at a place. If H=0.4xx10^(-4) T at the place, then induced emf between the axle the rim of the wheel is

A copper disc of radius 20cm makes 1200 revolution per minute about its axis which is parallel to a uniform magnetic field fo 0.01 tesla . Find the potential difference between the centre and the edge of the disc.

A uniform circular metal disc of radius R is rotating about a vertical axis passing through its centre and perpendicular to its plane with constant frequency f. If B_(H) and B_(V) are horizontal and vertical components of the Earth's magnetic field respectively, then the induced e.m.f between its centre and the rim is

A copper disc of radius 10 cm rotates 20 times per scond with its axis parallel to a uniform magnetic field of 0.5 tesla . Calculate the induced emf between the centre and the edge of the disc.