A metallic rod of length $l$ is rotated with an angular speed $\omega$ in a uniform magnetic field $B$ perpendicular to the rod and its axis of rotation. One end of the rod is hinged at the center of rotation. If the other end makes contact with a circular conducting ring through a brush, what is the magnitude of the emf induced between the center and the ring?

A helicopter rises vertically with a speed of ${\rm{100 }}\,{\rm{m}}{{\rm{s}}^{{\rm{ - 1}}}}$. If helicopter has length ${\rm{10}}\,\,{\rm{m}}$ and horizontal component of earth’s magnetic field is $5\,\, imes {10^{ - 3}}\,\,{\rm{Wb}}{{\rm{m}}^{ - 2}}$,then the induced emf between the tip of nose and tail of helicopter is

A straight conductor of length $4\,\,m$ moves at a speed of $10\,\,m/s$. When the conductor makes an angle of ${30^0}$ with the direction of magnetic field of induction of $0.1\,\,wb.{m^2}$ then induced emf is

A horizontal straight wire ${\rm{20}}\,{\rm{ m}}$ long extending from east to west is falling with a speed of ${\rm{5}}{\rm{.0}}\,\,{\rm{m}}{{\rm{s}}^{ - 1}}$,at right angles to the horizontal component of the earth’s magnetic field $0.030\,\, imes \,\,{10^{ - 4}}\,\,{\rm{Wb}}{{\rm{m}}^{ - 2}}{\rm{.}}\,{\rm{}}$ the instantaneous value of the emf induced in the wire will be

A wire of length $1\,\,m$ is moving at a speed of $2\,\,m{s^{ - 1}}$ perpendicular to its length and in a homogenous magnetic field of $0.5\,\,T$. The ends of the wire are joined to a circuit of resistance $6\,\,{\rm{\Omega }}$. The rate at which work is being done to keep the wire moving at constant speed is

The wing span of an aeroplane is $20\,\,metre$. It is flying in a field, where the vertical component of magnetic field of earth is $5 imes {10^{ - 5}}\,tesla$, with velocity $360\,\,km/h$. The potential difference produced between the blades will be

A square loop of side 10 cm is moved with a velocity of 5 m/s perpendicular to a magnetic field of 0.5 T. The emf induced in the loop is:

A copper rod of length $l$ is rotated about one end perpendicular to a uniform magnetic field $B$ with constant angular velocity $\omega$. The induced emf between the ends of the rod is $\epsilon$. If the length of the rod is doubled and the angular velocity is halved, the new induced emf will be:

The self induced emf in a coils of ${\rm{0}}.{\rm{4}}\,\,{\rm{henry}}$ self inductance when current in it is changing at the rate of ${\rm{50}}\,\,{\rm{A}}{{\rm{s}}^{{\rm{ - 1}}}}$, is

The expression for magnetic induction inside a solenoid of length L, carrying a current i and having N number of turns is

A non-magnetic, conducting disc is rotating in a uniform magnetic field perpendicular to its plane. What would happen if the disc's rotation speed increases?