The frequency of a light ray having a wavelength of $3000 \ \mathring A$ is

Two monochromatic light waves of amplitudes $3A$ and $2A$ interfering at a point have a phase difference of $60^{\circ}$. The intensity at that point will be proportional to.......$A^2$

Two point sources $S_1$ and $S_2$ separated by a distance $10 \mu m$ emit light waves of wavelength $4 \mu m$ in phase. $A$ circular wire of radius $40 \mu m$ is placed around the sources as shown in the figure,where $O$ is the centre of the circle and $OS_1 = OS_2$. Then:

Two coherent sources of light interfere. The intensity ratio of two sources is $1:4$. For this interference pattern,if the value of $\frac{I_{\max} + I_{\min}}{I_{\max} - I_{\min}}$ is equal to $\frac{2\alpha + 1}{\beta + 3}$,then the value of $\frac{\alpha}{\beta}$ will be:

Two identical light waves having phase difference $\phi$ propagate in the same direction. When they superpose,the intensity of the resultant wave is proportional to

What is interference?