Motional EMF — Prelims Questions

A straight conductor of length $0.2,\text{m}$ is moved with a constant velocity of $5,\text{m/s}$ perpendicular to a uniform magnetic field of $0.5,\text{T}$. What is the magnitude of the motional EMF induced across the conductor?

A conducting rod of length $L$ is rotated with a constant angular velocity $\omega$ about one of its ends in a uniform magnetic field $B$ perpendicular to the plane of rotation. Which of the following expressions correctly represents the motional EMF induced across the rod?

A metallic rod of length $1,\text{m}$ is held horizontally in an East-West direction and is allowed to fall freely from a height of $10,\text{m}$. The horizontal component of the Earth's magnetic field is $0.3 \times 10^{-4},\text{T}$. What is the EMF induced across the rod just before it hits the ground? (Take $g = 10,\text{m/s}^2$)

A conducting rod $PQ$ of length $L$ is moving with a uniform velocity $v$ parallel to a long straight wire carrying a steady current $I$. The rod is at a distance $r$ from the wire and its length is perpendicular to the wire. What is the motional EMF induced across the rod?

A square loop of side $a$ is moving with velocity $v$ into a uniform magnetic field $B$ directed perpendicular to the plane of the loop. The resistance of the loop is $R$. What is the magnitude of the induced current in the loop at the instant it enters the field?

A conducting rod of length $L$ is moving with a velocity $\vec{v}$ in a uniform magnetic field $\vec{B}$. The motional EMF induced across the rod is given by $( \vec{v} \times \vec{B} ) \cdot \vec{L}$. Under what condition will the induced EMF be zero?