If the ratio of the intensities of two waves producing interference is $49: 16$,then the ratio of the resultant maximum intensity to minimum intensity will be

The figure shows two point sources which emit light of wavelength $\lambda$ in phase with each other and are at a distance $d = 5.5 \lambda$ apart along a line which is perpendicular to a large screen at a distance $L$ from the center of the sources. Assume that $d$ is much less than $L$. Which of the following statement$(s)$ is (are) correct?

When two light waves of equal intensity superimpose,the maximum intensity obtained is $I$. If the intensity of one of the waves is quadrupled,then the maximum intensity obtained is

Two waves having amplitudes in the ratio $5:1$ produce interference. The ratio of the maximum to minimum intensity is

What are coherent sources and incoherent sources?

If $L$ is the coherence length and $c$ is the velocity of light,the coherence time is