Two particles A, B are moving on two concentric circles of radii R₁ and R₂ with equal angular speed $$\omega $$. At t = 0, their positions and direction of motion are shown in the figure. :



The relative velocity $${\overrightarrow V _A} - {\overrightarrow V _B}$$ at t = $${\pi \over {2\omega }}$$ is given by :

The mean intensity of radiation on the surface of the Sun is about 10⁸ W/m² . The rms value of the corresponding magnetic field is closet to :

A 10 m long horizontal wire extends from North East to South West. It is falling with a speed of 5.0 ms^–1, at right angles to the horizontal component of the earth's magnetic field of 0.3 $$ \times $$ 10^–4 Wb/m². The value of the induced emf in wire is :

An alpha-particle of mass m suffers 1-dimensional elastic collision with a nucleus at rest of unknown mass. It is scattered directly backwards losing, 64% of its initial kinetic energy. The mass of the nucleus is