$A$ ray of light from a monochromatic point source of light is incident at a point on the screen. If a thin mica film of thickness $t$ and refractive index $n$ is introduced in its path,then the optical path

Two coherent monochromatic point sources $S_1$ and $S_2$ of wavelength $\lambda = 600 \ nm$ are placed symmetrically on either side of the centre of the circle as shown. The sources are separated by a distance $d = 1.8 \ mm$. This arrangement produces interference fringes visible as alternate bright and dark spots on the circumference of the circle. The angular separation between two consecutive bright spots is $\Delta \theta$. Which of the following options is/are correct?
$[A]$ $A$ dark spot will be formed at the point $P_2$
$[B]$ At $P_2$ the order of the fringe will be maximum
$[C]$ The total number of fringes produced between $P_1$ and $P_2$ in the first quadrant is close to $3000$
$[D]$ The angular separation between two consecutive bright spots decreases as we move from $P_1$ to $P_2$ along the first quadrant

The interference pattern is obtained with two coherent light sources of intensity ratio $4:1$. If the ratio $\frac{I_{\max} + I_{\min}}{I_{\max} - I_{\min}}$ is $\frac{5}{x}$,then the value of $x$ will be equal to:

Two coherent sources whose intensity ratio is $64: 1$ produce interference fringes. The ratio of intensities of maxima and minima is

Which of the following is not a correct statement?

If the ratio of amplitudes of two interfering waves is $4: 3$,then the ratio of maximum and minimum intensity is