Two coherent light beams of intensity 2I and 18I are superposed with each other. The maximum and minimum possible intenstities in the resulting beam are

32I, 8I

The correct answer is Option (2) → 32I, 8I

$I_{max}∝|E_{max}|^2=(E_1+E_2)^2$

where,

$I_{max}$ = max. intensity

$I_{max}=(\sqrt{2I}+\sqrt{18I})^2$

$=I(\sqrt{2}+3\sqrt{2})^2=I(4\sqrt{2})^2$

$=32I$

$I_{min}∝|E_{min}|^2=(E_1-E_2)^2$

$=(\sqrt{2I}+\sqrt{18I})^2$

$=8I$