Two waves of intensity ratio 9:1 interfere to produce fringes in a young's double-slit experiment, the ratio of  intensity at maxima  to the intensity at minima is

1.  4:1

2.  9:1

3.  81:1

4.  9:4

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

1.$\frac{\sqrt{n}}{n+1}$             

2. $\frac{2\sqrt{n}}{n+1}$

3. $\frac{\sqrt{n}}{{\left(n+1\right)}^2}$         

4.$\frac{2\sqrt{n}}{{\left(n+1\right)}^2}$

Two coherent sources of light can be obtained by:

(1) Two different lamps

(2) Two different lamps but of the same power

(3) Two different lamps of the same power and have the same colour

(4) None of the above

Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are 

(1) 5I and I

(2) 5I and 3I

(3) 9I and I

(4) 9I and 3I

Soap bubble appears coloured due to the phenomenon of:
1. Interference
2. Diffraction
3. Dispersion
4. Reflection

Interference was observed in interference chamber when the air was present, now the chamber is evacuated and if the same light is used, a careful observer will see

(1) No interference

(2) Interference with bright bands

(3) Interference with dark bands

(4) Interference in which width of the fringe will be slightly increased

Two coherent sources have intensity in the ratio of $\frac{100}{1}$. Ratio of (intensity)_max/(intensity)_min is: 
1. $\frac{1}{100}$
2. $\frac{1}{10}$
3.$\frac{10}{1}$
4. $\frac{3}{2}$

If two waves represented by $y_1=4\sin \omega t$ and $y_2=3\sin \left(\omega t+\frac{{\displaystyle \pi }}{{\displaystyle 3}}\right)$ interfere at a point, the amplitude of the resulting wave will be about 

(1) 7

(2) 6

(3) 5

(4) 3.5

Two coherent sources of intensities, I₁ and I₂ produce an interference pattern. The maximum intensity in the interference pattern will be 

(1) I₁ + I₂

(2) $I_1^2+I_2^2$

(3) (I₁ + I₂)²

(4) ${(\sqrt{I_1}+\sqrt{I_2})}^2$

Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is $\frac{\pi }{2}$ at point A and π at point B. Then the difference between the resultant intensities at A and B is 

(1) 2I

(2) 4I

(3) 5I

(4) 7I