A ceiling fan having 3 blades of length 80 cm each is rotating with an angular velocity of 1200 rpm. The magnetic field of earth in that region is 0.5 G and the angle of dip is 30°. The emf induced across the blades is $N\pi \times {10}^{-5}$ V. The value of N is ______.                            [2024]

A horizontal straight wire 5 m long extending from east to west falling freely at right angle to horizontal component of earth's magnetic field $0.60\times {10}^{-4}$ $Wb{m}^{-2}$. The instantaneous value of emf induced in the wire when its velocity is $10m{s}^{-1}$ is _____ $\times {10}^{-3}$ V.                           [2024]

A rod of length 60 cm rotates with a uniform angular velocity 20 rad ${\mathrm{s}}^{-1}$ about its perpendicular bisector, in a uniform magnetic field 0.5 T. The direction of magnetic field is parallel to the axis of rotation. The potential difference between the two ends of the rod is ______ V.     [2024]

A square loop PQRS having 10 turns, area $3.6\times {10}^{-3}{\mathrm{m}}^2$ and resistance 100 $\Omega$ is slowly and uniformly being pulled out of a uniform magnetic field of magnitude B = 0.5 T as shown. Work done in pulling the loop out of the field in 1.0 s is ___ $\times {10}^{-6}\mathrm{J}$.              [2024]

A rectangular loop of sides 12 cm and 5 cm, with its sides parallel to the x-axis and y-axis respectively, moves with a velocity of 5 cm/s in the positive x-axis direction, in a space containing a variable magnetic field in the positive z-direction. The field has a gradient of ${10}^{-3}$ T/cm along the negative x-direction and it is decreasing with time at the rate of ${10}^{-3}$ T/s. If the resistance of the loop is 6 $\mathrm{m\Omega }$, the power dissipated by the loop as heat is ______ $\times {10}^{-9}$ W.        [2024]