The slit width, when a light of wavelength 6500 Å is incident on a slit, if first minima for red light is at 30°, is :

• 1 × 10^-6 m

• 5.2 × 10^-6 m

• 1.3 × 10^-6 m

• 2.6 × 10^-6 m

In single slit diffraction pattern

• central fringe has negligible width than others

• all fringes are of same width

• central fringe does not exist

• none of the above

The ratio of intensities of two waves is 1: 9. The waves interference, what will be the ratio of maximum and minimum intensities?

• 1:4

• 4:1

• 3:2

• 2:3

Two coherent monochromatic light beams of intensities I and 9I are superimposed.The maximum and the minimum intensities of the resultant beams are

• 10 I and zero

• 10 I and 8 I

• 10 I and 4 I

• 16 I and 4 I

205.

In a single slit diffraction pattern, the distance between the first minimum on the left and the first minimum on the right is 5 mm. The screen on which the diffraction pattern is displayed is at a distance of 80 cm from the slit. The, wavelength is 6000 A. The slit width (in mm) is about

• 0.576

• 0.348

• 0.192

• 0.096

To demonstrate the phenomenon of interference we require two sources which emit radiations of

• nearly the same frequency

• the same frequency

• different wavelengths

• the same frequency and having a definite phase relationship

In Young's experiment, the wavelength of red light is 7800 $\stackrel{\circ }{\mathrm{A}}$ and that of blue light is 5200 $\stackrel{\circ }{\mathrm{A}}$ . The value of n for which (n + 1)th blue band coincides with nth red band is

• 1

• 2

• 3

• 4

The phenomenon of polarization of light indicates that

• light is a longitudinal waves

• light is transverse wave

• light if not a wave

• light travels with the velocity of 3x 10⁸ m/s

In Young's double slit experiment one slit is covered with red filter and another slit is covered by green filter, then interference pattern will be

• red

• green

• yellow

• invisible

In Young's experiment, if separation between slits is made half, then fringe width will become

• double

• four times

• half

• remains same