Intensity Explanation in YDSE

Q.

In Youngs double slit experiment if the slits widths are in the ratio $1:9$, the ratio of the intensities at minima to that at maxima will be

1. $1$

2. $\frac{1}{9}$

3. $\frac{1}{4}$

4. $\frac{1}{3}$

Q.

The intensity ratio of two waves is 1 : 16. The ratio of their amplitudes is

[EAMCET 1983]

1. 1 : 16

2. 4 : 1

3. 1 : 4

4. 2 : 1

Q. In a double slit experiment, the two slits are 1 mm apart and the screen is placed 1 m away. A monochromatic light of wavelength 500 nm is used. What will be the width of each slit for obtaining ten maxima of double slit within the central maxima of single slit pattern?

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

1. $\frac{4}{9}$
2. $\frac{9}{4}$
3. $\frac{121}{49}$
4. $\frac{49}{121}$

Q.

Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are
[IIT-JEE 1988; RPMT 1995; AIIMS 1997; MP PMT 1997;MP PET 1999; BHU 2002; KCET 2000, 05]

1. 5I and I

2. 5I and 3I

3. 9I and I

4. 9I and 3I

Q. The light from a torch is normally incident on the surface at intensity of illumination $I_1$. If the surface is tilted to ${45}^{\circ }$ from initial position, then what will be intensity of illumination $I_2$ on the surface in terms of $I_1$ ?

1. $I_2=\frac{I_1}{\sqrt{2}}$
2. $I_2=I_1$
3. $I_2=2I_1$
4. $I_2=4I_1$

Q. A parallel beam of light of wavelength 560 nm falls on a thin film of oil (refractive index = 1.4). What should be the minimum thickness of the film so that it strongly reflects the light?

Q. In Young's double slit experiment, the intensity of light at a point on the screen where the path difference is $\lambda$ is K unit; $\lambda$ being the wavelength of light used. The intensity at a point where the path difference is $\frac{\lambda }{4}$ will be:

1. $\frac{K}{4}$
2. $\frac{K}{2}$
3. K
4. zero

Q. The intensities of two light sources are I and 9I respectively. If the phase difference between the waves emitted by them is $\pi$, then the resultant intensity at the point of observation will be

1. 3I
2. 4I
3. 10I
4. 82I

Q. In Young's double slit experiment, the intensity of light at a point on the screen where the path difference is $\lambda$ is K unit; $\lambda$ being the wavelength of light used. The intensity at a point where the path difference is $\frac{\lambda }{4}$ will be:

1. $\frac{K}{4}$
2. $\frac{K}{2}$
3. K
4. zero

Q. The light from a torch is normally incident on the surface at intensity of illumination $I_1$. If the surface is tilted to ${45}^{\circ }$ from initial position, then what will be intensity of illumination $I_2$ on the surface in terms of $I_1$ ?

1. $I_2=\frac{I_1}{\sqrt{2}}$
2. $I_2=I_1$
3. $I_2=2I_1$
4. $I_2=4I_1$

Q. Two coherent monochromatic light beams of intensities $I$ and $4I$ are superimposed. The maximum and minimum possible intensities, in the resulting beam, are:

1. $5I\text{and}3I$
2. $5I\text{and}I$
3. $9I\text{and}I$
4. $9I\text{and}3I$

Q. A point source emitting light uniformly in all directions is placed 60 cm above a table-top. The illuminance at a point on the table-top, directly below the source, is 15 lux. Find the illuminance at a point on the table-top 80 cm away from the first point.