NEET Physics Electromagnetic Induction MCQs

A conducting rod of length $l$ rotates with a constant angular velocity $\omega$ about one end in a uniform magnetic field $B$ perpendicular to the plane of rotation. A capacitor $C$ is connected in series with the rod and a resistance $R$. If the steady state charge on the capacitor is $Q$, which of the following expressions is correct?

A conducting square loop of side $l$ and resistance $R$ is moving with a constant velocity $v$ perpendicular to one of its sides and entering a uniform magnetic field $B$ perpendicular to the plane of the loop. What is the magnitude of the induced current in the loop as a function of time $t$, where $t=0$ is the instant when the loop starts entering the field?

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 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:

A conducting rod of length $l$ moves with a constant velocity $v$ in a uniform magnetic field $B$. The field is perpendicular to the rod and the velocity. The rod slides on conducting rails forming a closed circuit with resistance $R$. If the force required to keep the rod moving with constant velocity is $F$, which expression correctly relates $F$, $B$, $l$, $v$, and $R$?

Two coaxial solenoids of radii $r_1$ and $r_2$ ($r_2 > r_1$) have the same length $l$ and the same number of turns $N$. If the current in the outer solenoid changes at a rate of $\frac{dI}{dt}$, what is the induced emf in the inner solenoid?

A square loop of side $a$ and resistance $R$ is placed in a spatially uniform magnetic field $B$ that is perpendicular to its plane. The magnetic field decays exponentially with time according to $B(t) = B_0e^{-t/au}$. What is the total charge that flows through the loop from $t=0$ to $t=\infty$?

Two identical coils, each of inductance $L$, are connected in series and placed such that their mutual inductance is $M$. If the current in the coils is changing at a rate $\frac{dI}{dt}$, what is the total induced emf across the series combination?

A toroidal solenoid with $N$ turns and mean radius $r$ carries a current $I$. A single loop of wire is wrapped around the toroid. If the current in the solenoid is changing at a rate $\frac{dI}{dt}$, what is the induced emf in the single loop?

Two identical coaxial circular coils, each of radius $R$ and $N$ turns, are placed a distance $d$ apart, where $d << R$. A current $I$ flows through both coils in the same direction. A small circular loop of radius $r$ ($r << R$) and resistance $\rho$ is placed coaxially midway between the coils. If the current in the larger coils is now varied at a rate of $\frac{dI}{dt}$, what is the induced current in the small loop?