NEET Physics Electromagnetic Induction Motional Emf 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 $R$?

A conducting rod of length $l$ moves with a constant velocity $v$ perpendicular to a uniform magnetic field $B$. The emf induced between the ends of the rod is:

A square loop of side $a$ is moving with velocity $v$ in a uniform magnetic field $B$ perpendicular to its plane. The induced emf in the loop when its one side is outside the field is:

A metal disc of radius $r$ rotates with an angular velocity $\omega$ in a uniform magnetic field $B$ perpendicular to its plane. The emf induced between the center and the rim of the disc is:

A conducting rod of length $0.5$ m falls freely under gravity in a region where a horizontal magnetic field of $0.4$ T exists perpendicular to the length of the rod. If the induced emf across the ends of the rod is $0.2$ V, the velocity of the rod is:

A rectangular loop is placed in a uniform magnetic field with its plane perpendicular to the field. If the loop starts rotating about one of its sides with angular velocity $\omega$, the maximum induced emf in the loop is proportional to: