An aircraft with a wingspan of $40 \text{ m}$ flies with a speed of $1080 \text{ km h}^{-1}$ in the eastward direction at a constant altitude in the northern hemisphere,where the vertical component of the earth's magnetic field is $1.75 \times 10^{-5} \text{ T}$. The emf developed between the tips of the wings is: (in $\text{ V}$)

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

$A$ conducting bar is pulled with a constant speed $v$ on a smooth conducting rail. The region has a steady magnetic field of induction $B$ as shown in the figure. If the speed of the bar is doubled then the rate of heat dissipation will

$A$ metal rod of length $L$ rotates about one end at origin with a uniform angular velocity $\omega$. The magnetic field radially falls off as $B(r) = B_0 e^{-\lambda r}$; $\lambda$ being a positive constant. The emf induced (neglecting the centripetal force on electrons in the rod) is :

$A$ wheel with radial metal spokes $1 \ m$ in length is rotated in a magnetic field of $0.5 \times 10^{-4} \ T$ normal to the plane of the wheel. If the induced emf between the rim and axle is $\pi / 3000 \ V$,then the rotational speed of the wheel in revolutions per minute is

$A$ wire having mass $m$ and length $l$ can freely slide on a pair of parallel smooth horizontal rails placed in a vertical magnetic field $B$. The rails are connected by a capacitor of capacitance $C$. The electric resistance of the rails and the wire is zero. If a constant force $F$ acts on the wire as shown in the figure,then the acceleration of the wire is given by: