A circular coil of radius 10 cm, 500 turns and resistance `2Omega` is placed with its plane, perpendicular to the horizontal component of the earth's magnetic field. It is rotated about its vertical diameter through `180^@` in 0.25 s. The induced e.m.f. in the coil is ..... (Take `H_E=3.0xx10^(-5) T)`

In a region of a uniform magnetic induction B=10^(-3)T , a circular coil of raidus 40cm and resistance pi^(3)Omega is rotated about an axis which is perpendicular to the direction of vecB and which forms a diameter of the coil. If the coil rotates at 400 r.p.m., the amplitude of the alternating current induced in the coil is

The horizontal component of earths's magnetic field at a place is 0.3 xx 10^-4T . If the angle of dip is 60^@ , what is the total earth's magnetic field?

A horizontal straight wire 10 m long extending from east to west is falling with a speed of 5.0 m s^-1 , at right angles to the horizontal component of the earth’s magnetic field, 0.30 xx 10^-4 Wb m^-2 , What is the instantaneous value of the emf induced in the wire?

A circular copper disc 10 cm in radius rotates at 20pi rad/s about an axis through its centre and perpendicular to the disc. A uniform magnetic field of 0.2 T acts perpendicular to the disc. What is the induced current if the resistance of the disc is 2Omega ?

The magnetic needle of a tangent galvanometer is deflected at an angle 30^(@) due to a magnet. The hoeizontal component of earth's magnetic field 0.34xx10^(-4)T is along the plane of the coil. The magnetic intensity is

A circular coil of 25 turns and radius of 12 cm is placed in a uniform magnetic field of 0.5 T normal to the plane of coil. If the current in the coil is 5 A, then total torque experienced by the coil.

The vertical component of the earth's magnetic field at a given place is sqrt3 times its horizontal component. If total intensity of earth's magnetic field at the place is 0.4G, find the vale of angle of dip

In a ceiling fan, each blade rotates in a circle of radius 0.5 m. If the fan makes 2 rotation per second and the vertical component of the earth's magnetic field is 8xx 10^-5 T , calculate the emf induced between the inner and outer ends, of each blade.

A second coil of 300 turns is wound closely on the toroid above. If the current in the primary coil is increased from zero to 2.0 A in 0.05 s, obtain the induced e.m.f. in the second coil.