Electromagnetic...

The number of turns in the coil of an ac generator is $$5000$$ and the area of the coil is $$0.25  \mathrm { m } ^ { 2 }$$ . The coil is rotated at the rate of $$100$$ cycles/sec in a magnetic field at $$0.2 T$$ . The peak value of the emf generated is nearly

An electron and a proton both having the same kinetic energy enters region of uniform magnetic field. In a plane perpendicular to the field.If their masses are denoted by in ans respectively then the ration the radii (electron to produced) of their circular orbits is

The magnetic field in a certain cylindrical region is changing with time according to the law B=$$B=[16-4t^{2}]$$ Tesla.. The induced electric field at point P at time t=2 sec.

The coefficient of self induction of two inductor coils are 20 mH and 40 mH respectively. If the cols are connected in series so as to support each other and the resultant inductance is 80 mH then the value of mutual inductance between the coils will be 

Length of one metal rod is $$1$$ meter. $$2T$$ is the intensity of the magnetic field. When this rod is rotating with the frequency of $$10 Hz$$ perpendicular to the field line by keeping its one end fixed as centre, induced emf is 

A uniform magnetic field exists exists in the region given by  $$\overrightarrow B  = \left( {3\widehat i + 4\widehat j + 5\widehat k} \right)T$$. A rod of length 1 m placed along y-axis is moved along x-axis with constant  velocity 1 m/s, then induced emf in the rod is.

A long straight wire is placed along the axis of a circular ring of radius R. The mutual inductance of this system is

A thin non-conducting ring of mass m carrying a charge q can freely rotate about its axis .Initially the ring is at rest and no magnetic field was present. When a uniform magnetic field is switched on, perpendicular to the plane of the ring, and increased with time according to the relation dB/dt=k the angular velocity of the ring as a function of is

The current is reduced from 3 amp to zero in 0.001 sec. in the primary coil. It induces an emf of 15000 volts in the secondary. The value of coefficient of mutual inductance in Henry will be -

A coil has self-inductance L. If number of turns per unit length is halved and radius is doubled, self inductance become