NEET Physics MCQs

In an induction coil, the coefficient of mutual inductance is 4H. If current of 5A in the primary coil is cut off $i$ 1/ 1500s, the emf at the terminals of the secondary coil will be

What is the self-inductance of a coil which produces 5 V when the current changes from 3 A to 2 A in one millisecond?

A current of 10 A in the primary coil of a circuit is reduced to zero. If the coefficient f mutual inductance is 3H and emf induced in secondary coil is 30 kV, time taken for the change of current is

Flux $\phi$ (in weber) in a closed-circuited of resistance varies with time according to the equation $\phi = \left( {8{t^3} + 6{t^2} + 2} \right)$ where t is in second. The magnitude of the induced current at t=1s will be

The flux linked with a coil at any time t is given as $\phi = \left( {10{t^2} - 50t + 250} \right)\,\,Wb$. The induced emf at t = 3s is?

Current in a circuit falls from 5.0 A to 0 A in 0.1 s. If an average emf of 200 V is induced, estimate the self-inductance of the circuit

The self inductance of a coil is $5\,\,henry$, a current of $1\,\,amp$ change to $2\,\,amp$ within $5\,\,second$ through the coil. The value of induced e.m.f. will be

A square loop of wire, side length ${\rm{10}}\,\,{\rm{cm}}$ is placed at angle of ${\rm{45}}^\circ$ with a magnetic field that changes uniformly from ${\rm{0}}{\rm{.1 T}}$ to zero in ${\rm{0}}{\rm{.7 s}}$. The induced current in the loop (its resistance is ${\rm{1}}\,\,{\rm{\Omega }})$ is

A rectangular loop of sides ${\rm{10}}\,{\rm{cm}}$ and ${\rm{5}}\,{\rm{cm}}$ with a cut is stationary between the pole pieces of an electromagnet. The magnetic field of the magnet is normal to the loop. The current feeding the electromagnet is reduced so that the field decreased from its initial value of ${\rm{0}}{\rm{.3 T}}$ at the rate of $0.02\,\,{\rm{\Omega }}$. If the cut is joined and the loop has a resistance of $2.0\,\,{\rm{\Omega }}$, the power dissipated by the loop as heat is

A circular wire of radius $r$ rotates about its own axis with angular speed $\omega$ in a magnetic field $B$ perpendicular to its plane, then the induced emf is