Electromagnetic Induction — Prelims Questions

A square loop of side $10\,\text{cm}$ and resistance $0.5\,\Omega$ is placed vertically in the east-west plane. A uniform magnetic field of $0.10\,\text{T}$ is set up across the plane in the north-east direction. The magnetic field is decreased to zero in $0.70\,\text{s}$ at a steady rate. The magnitude of induced current during this time interval is:

A coil of self-inductance $L$ is connected in series with a bulb and an AC source. Brightness of the bulb decreases when:

A metal rod of length $1\,\text{m}$ is rotated about one of its ends with a uniform angular velocity of $10\,\text{rad/s}$. If a uniform magnetic field of $0.5\,\text{T}$ exists parallel to the axis of rotation, then the EMF induced between the ends of the rod is:

A circular coil of radius $R$ and $N$ turns is rotated with an angular velocity $\omega$ in a uniform magnetic field $B$. The maximum EMF induced in the coil is:

A current of $2.5\,\text{A}$ flows through a coil of self-inductance $5\,\text{H}$. The energy stored in the magnetic field of the coil is:

A bar magnet is moved rapidly towards a coil. The induced EMF is $E$. If the magnet is moved away from the coil with the same speed, the induced EMF will be: