Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are:
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Question

Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are:

G1 Physics · Accepted Answer

Amplitudes are proportional to square roots of intensities. For I and 4I, amplitudes are √I and 2√I. Hence Iₘₐₓ=(3√I)²=9I and Iₘᵢₙ=(√I)²=I. Option C.