The intensity ratio of two waves is 9: 1 . These waves produce the event of interference. The ratio of maximum to minimum intensity will be-

1. 1: 9

2. 9: 1

3. 1: 4

4. 4: 1

If an interference pattern has maximum and minimum intensities in 36: 1 ratio then what will be the ratio of amplitudes

1. 5: 7

2. 7: 4

3. 4: 7

4. 7: 5

Light of wavelength 589.3 nm is incident normally on the slit of width 0.1 mm. What will be the agular width of the central diffreaction maximum at a distance of 1 m from the slit

1. $0.68°$

2. $1.02°$

3. $0.34°$

4. None of these

In a single-slit diffraction experiment, the width of the slit is reduced by half. Which of the following needs to be done if the width of the central maxima has to remain the same

1. Reduce the distance between the slit and screen by half

2. Reduce the distance between the slit and the screen to ${\left(\frac{1}{4}\right)}^{th}$ the original separation

3. Double the distance between the slit and the screen

4. No need to do anything, as the width of the central maxima does not depend on the slit width

In Young's experiment the wavelength of red light is 7.5 x 10^-5 cm. and that of blue light 5.0 x 10^-5 cm. The value of n for which (n+1)^th the blue bright band coincides with n^th red band is -

1. 8

2. 4

3. 2

4. 1

Colours of thin films result from

Or

On a rainy day, a small oil film on water show brilliant colours. This is due to

1. Dispersion of light

2. Interference of light

3. Absorption of light

4. Scattering of light

In a Young's double slit experiment the intensity at a point where the path difference is $\frac{\lambda }{6}$ ($\lambda$ being the wavelength of the light used) is I. If I₀ denotes the maximum intensity, $\frac{I}{I_0}$ is equal to

1. $\frac{1}{\sqrt{2}}$

2. $\frac{\sqrt{3}}{2}$

3. 1/2

4. 3/4

An optically active compound 

1. Rotates the plane polarised light

2. Changes the direction of polarised light

3. Does not allow plane polarised light to pass through

4. None of the above

In a Young's experiment, the separation between the slits is 0.10 mm, the wavelength of light used is 600 nm and the interference pattern is observed on a screen 1.0 m away. Find the separation between the successive bright fringes.

1. 6.6 mm

2. 6.0 mm

3. 6 m

4. 6 cm.

Intensities of the two waves of light are I and 4I. The maximum intensity of the resultant wave after superposition is 

1. 5I

2. 9I

3. 16I

4. 25I