What are the postulates of Bohr's model of an atom?

(N/A) The postulates put forth by Neils Bohr regarding the model of an atom are as follows:
$(i)$ Only certain special orbits,known as discrete orbits of electrons,are allowed inside the atom.
$(ii)$ While revolving in these discrete orbits,the electrons do not radiate energy. These orbits are called energy levels or shells. Energy levels in an atom are represented by circles. These orbits are denoted by the letters $K, L, M, N, \dots$ or by the numbers $n = 1, 2, 3, 4, \dots$.