Two coherent point sources emit in phase and are separated by 4.4λ. How many points of maximum intensity lie strictly between the sources on the straight line joining them?
Physics · Wave Optics · interferece of light and huygen principle
JEE Mains NEET JEE Advanced

Question

Two coherent point sources emit in phase and are separated by 4.4λ. How many points of maximum intensity lie strictly between the sources on the straight line joining them?

G1 Physics · Accepted Answer

For maxima, Δ = nλ. Between the sources, Δ can have magnitudes up to 4.4λ. Allowed n values are 0, 1, 2, 3, 4. The central maximum gives one point and the four non-zero orders give two points each. Thus, number of maxima = 1+2×4 = 9. Hence the answer is 9.