A metallic meter stick moves with a velocity of 2 ms^–1 in a direction perpendicular to its length and perpendicular to a uniform magnetic field of magnitude 0.2 T. Find the emf induced between the ends of the stick.

Figure shows a circular wheel of radius 10.0 cm whose upper half, shown dark in the figure, is made of iron and the lower half of wood. The two junctions are joined by an iron rod. A uniform magnetic field B of magnitude 2.00 × 10^–4 T exists in the space above the central line as suggested by the figure. The wheel is set into pure rolling on the horizontal surface. If it takes 2.00 seconds for the iron part to come down and the wooden part to go up, find the average emf induced during this period.

A 20 cm long conducting rod is st into pure translation with a uniform velocity of 10 cm s^–1 perpendicular to its length. A uniform magnetic field of magnitude 0.10 T exists in a direction perpendicular to the plane of motion.

(a) Find the average magnetic force on the free electrons of the rod.

(b) For what electric field inside the rod, the electric force on a free electron will balance the magnetic force? How is this electric field created?

(c) Find the motional emf between the ends of the rod.

A 10 m wide spacecraft moves through the interstellar space at a speed 3 × 10⁷ m s^–1. A magnetic field B = 3 × 10^–10 T exists in the space in a direction perpendicular to the plane of motion. Treating the spacecraft as a conductor, calculate the emf induced across its width.

The two rails of a railway track, insulated from each other and from the ground, are connected to a millivoltmeter. What will be the reading of the millivoltmeter when a train travels on the track at a speed of 180 km h^–1? The vertical component of earth’s magnetic field is 0.2 × 10^–4 T and the rails are separated by 1 m.