Write the important characteristic features by which the interference can be distinguished from the observed diffraction pattern.

OR

Explain the basic differences between the construction and working of a telescope and a microscope

Define the term ‘mobility’ of charge carriers. Write its S.I. unit.

The focal length of an equiconvex lens is equal to the radius of curvature of either face. What is the refractive index of the material of the lens?

State Bohr’s postulate of hydrogen atom which successfully explains the emission lines in the spectrum of hydrogen atom.

Use Rydberg formula to determine the wavelength of Hα line.

[Given: Rydberg constant R = 1.03 x 10⁷ m^–1]

State the two Kirchhoff’s rules used in electric networks. How are these rules justified?