To observe a stationary interference pattern formed by two light waves,it is not necessary that they must have :

The interference pattern is obtained with two coherent light sources of intensity ratio $n$. In the interference pattern,the ratio $\frac{I_{max} - I_{min}}{I_{max} + I_{min}}$ will be

Two light waves of intensities $I_1$ and $I_2$ having the same frequency pass through the same medium at a time in the same direction and interfere. The sum of the minimum and maximum intensities is

Two coherent sources $S_1$ and $S_2$ are separated by a distance four times the wavelength $\lambda$ of the source. The sources lie along the $y$-axis,whereas a detector moves along the $+x$-axis. Leaving the origin and far-off points,the number of points where maxima are observed is

In an interference experiment,two coherent waves $S_1$ and $S_2$ are represented by $y_1 = 10 \sin(\omega t)$ and $y_2 = 10 \sin(\omega t - \pi/6)$ respectively. When these waves superimpose to form an interference pattern,the maximum intensity is ....... (Assume $K = 1$)

Interference cannot be observed in two sodium lamps of equal power because the two waves do not have a .....