What is the cause of the force acting on a sliding conductor placed in a magnetic field?

In the given branch $AB$ of a circuit,a current $I = (10t + 5) \, A$ is flowing,where $t$ is time in seconds. At $t = 0$,the potential difference between points $A$ and $B$ $(V_A - V_B)$ is.....$V$.

$A$ rod closing the circuit shown in the figure moves along a $U$-shaped wire at a constant speed $v$ under the action of a force $F$. The circuit is in a uniform magnetic field perpendicular to the plane. Calculate $F$ if the rate of heat generation in the circuit is $Q$.

$A$ long rectangular conducting loop of width '$l$',mass '$m$',and resistance '$R$' is placed partly in a perpendicular magnetic field '$B$'. With what velocity should it be pushed downwards so that it may continue to fall without any acceleration? ($g = $ acceleration due to gravity)

$A$ circular metal plate of radius $R$ is rotating with a uniform angular velocity $\omega$ with its plane perpendicular to a uniform magnetic field $B$. Then the emf developed between the centre and the rim of the plate is

$A$ rod of length $2 \, m$ slides with a speed of $5 \, ms^{-1}$ on a rectangular conducting frame as shown in the figure. There exists a uniform magnetic field of $0.04 \, T$ perpendicular to the plane of the figure. If the resistance of the rod is $3 \, \Omega$, the current through the rod is