Two polaroids $P_1$ and $P_2$ are placed with their axis perpendicular to each other. Unpolarised light $I_o$ is incident on $P_1$. A third polaroid $P_3$ is kept in between $P_1$ and $P_2$ such that its axis makes an angle $45^\circ$ with that of $P_1$. The intensity of transmitted light through $P_2$ is

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

At the first minimum adjacent to the central maximum of a single slit diffraction pattern, the phase difference between the Huygen's wavelet from the edge of the slit and the wavelet from the midpoint of the slit is

A major breakthrough in the studies of cells came with the development of an electron microscope. This is because:

Two slits in Young's experiment have widths in the ratio of $1:25$. The ratio of intensity at the maxima and minima in the interference pattern $\frac{I_{max}}{I_{min}}$ is:

For a parallel beam of monochromatic light of wavelength $\lambda$, diffraction is produced by a single slit whose width $a$ is much greater than the wavelength of the light. If $D$ is the distance of the screen from the slit, the width of the central maxima will be:

In a diffraction pattern due to a single slit of width $a$, the first minimum is observed at an angle $30^\circ$ when light of wavelength $5000\text{ \AA}$ is incident on the slit. The first secondary maximum is observed at an angle of

In a double-slit experiment, when light of wavelength $400 \text{ nm}$ was used, the angular width of the first minima formed on a screen placed $1 \text{ m}$ away, was found to be $0.2^{\circ}$. What will be the angular width of the first minima, if the entire experimental apparatus is immersed in water? $\left(\mu_{\text{water}} = \frac{4}{3}\right)$

For Young's double-slit experiment, two statements are given below: Statement I: If screen is moved away from the plane of slits, angular separation of the fringes remains constant. Statement II: If the monochromatic source is replaced by another monochromatic source of larger wavelength, the angular separation of fringes decreases.