The de-Broglie wavelength $$(\lambda)$$ of a particle is related to its kinetic energy (E) as

For a purely inductive or a purely capacitive circuit, the power factor is

The electric field intensity on the surface of a solid charged sphere of radius '$$r$$' and volume charge density '$$\rho$$' is ($$\varepsilon_0=$$ permittivity of free space)

A body is said to be opaque to the radiation if (a, r and t are coefficient of absorption, reflection and transmission respectively)