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***In each paragraph 3 multiple choice questions have to be answered. Each question has four choices (A), (B), (C) and (D) out of which ONLY ONE is correct.*

*Paragraph:When a particle is restricted to move along x-axis between x = 0 and x = a, where a is of nanometre dimension, its energy can take only certain specific values. The allowed energies of the particle moving in such a restricted region, correspond to the formation of standing waves with nodes at its ends x = 0 and x = a. The wavelength of this standing wave is related to the linear momentum p of the particle according to the de Broglie relation. The energy of the particle of mass m is related to its linear momentum as E=p^{2}/2m. Thus, the energy of the particle can be denoted by a quantum number 'n' taking values 1,2,3,....(n = 1, called the ground state) corresponding to the number of loops in the standing wave. Use the model described above to answer the following three questions for a particle moving in the line x = 0 to x = a. Take h = 6.6x10^{−34}Js and e=1.6x10^{−19} C. *

The allowed energy for the particle for a particular value of n is proportional to