Intensity Explanation in YDSE

Q. Two slits in Youngs 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. $\frac{9}{4}$
2. $\frac{4}{9}$
3. $\frac{121}{49}$
4. $\frac{49}{121}$

Q.

The maximum number of possible interference maxima for slit separation is equal to twice the wavelength in Youngs double-slit experiment, which is

1. Infinite

2. Five

3. Three

4. Zero

Q. In a young’s double-slit experiment $\lambda$ = 500 nm, d = 1m and D = 1m. The minimum distance from the central maximum for which the intensity is half of the maximum intensity is

1. $2\times {10}^{-4}$m
2. $1.25\times {10}^{-4}$m
3. $4\times {10}^{-4}$m
4. $2.5\times {10}^{-4}$m

Q. Two identical sound waves $S_1$ and $S_2$ reach a point $P$ in phase. The resultant loudness at point is $\sqrt{n}\text{dB}$ higher than the loudness of $S_1$. Then, the value of $n$ is
[Take ${\log }_{10}2=0.3$]

Q.

A ray of light of intensity I is incident on a parallel glass-slab at a point A as shown in fig. It undergoes partial reflection and refraction. At each reflection 25% of incident energy is reflected. The rays AB and A'B' undergo interference. The ratio is

[IIT 1990]

1. 7 : 1

2. 49 : 1

3. 4 : 1

4. 8 : 1

Q. In Young's double slit experiment the two slits are $0.6mm$ distance apart. Interference pattern is observed on a screen at a distance $80cm$ from the slits. The first dark fringe is observed on the screen directly opposite to one of the slits. The wavelength of light will be _______ $nm.$

Q. In the young’s double slit experiment, the slit widths are in the ratio of 9:1. The ratio of the intensities at the maxima and minima will be

1. 3 : 1
2. 1 : 3
3. 1 : 4
4. 4 :1

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. 10I
2. 4I
3. 3I
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. K
3. zero
4. $\frac{K}{2}$

Q. The intensity of light at a distance $r$ from the axis of a long cylindrical source is proportional to :

1. $r$
2. $r^2$
3. $\frac{1}{r}$
4. $\frac{1}{r^2}$

Q. If the distance b/w The 1st maxima and 5th minima of a double slit pattern is 7mm and slits are separated by 0.15mm with the screen 50cm away from slits then find wavelength of light used.

Q. In the figure shown , if a parallel beam of white light is incident on the pair of the slits then the distance of the nearest white spot on the screen from $O$ is : [Assumed $d<<D,\lambda <<d]$

1. $0$
2. $\frac{d}{2}$
3. $\frac{d}{3}$
4. $\frac{d}{6}$

Q.

Two audio speakers are kept some distance apart and are driven by the same amplifier system. A person is sitting at a place $6.0m$ from one of the speakers and $6.4m$ from the other. If the sound signal is continuously varied from $500Hz$ to $5000Hz$, what are the frequencies for which there is a destructive interference at the place of the listener? Speed of sound in air $=320m/s$.

Q.

In the diffraction of a single slit experiment, if the slit width is half then the width of the central maxima will be

1. Remains the same

2. Doubled

3. Becomes four times.

4. Halved

Q.

The wavelength of the light used in Young’s double slit experiment is $\lambda$. The intensity at a point on the screen is I, where the path difference is $\frac{\lambda }{6}$. If $I_0$ denotes the maximum intensity, then the ratio of I and $I_0$ is:

1. 0.707

2. 0.75

3. 0.866

4. 0.5

Q.

The equation of two light waves are $y_1=6cos\omega t,y_2=8cos(\omega t+\varphi )$ the ratio of maximum to minimum intensities produced by the superposition of these wave will be

1. 1 : 49
2. 49 :1
3. 1 : 7
4. 7: 1

Q. In YDSE experiment, the spacing between the slits is d and wavelength of light used is 6000 Angstrom . If the angular width of a fringe formed on distant screen is 1 degree , then value of d is : a) 1 mm. b) 0.05 mm. c) 0.03 mm. d) 0.01 mm.

Q. If the intensity of two waves is $2$ and $3$ units, then average intensity of light in the overlapping region will be,

1. $2.5\text{units}$
2. $6\text{units}$
3. $5\text{units}$
4. $13\text{units}$

Q. Two coherent sources emit light waves which superimpose at a point where these can be expressed as
$E_1=E_0\sin (\omega t+\frac{\pi }{4})$
$E_2=2E_0\sin (\omega t-\frac{\pi }{4})$
Here, $E_1$ and $E_2$ are the electric field strengths of the two waves at the given point. If I is the intensity of wave expressed by field strength $E_1$, find the resultant intensity (in $I$).

Q. A gas mixture consists of $2.0$ moles of oxygen and $4.0$ moles of neon at temperature $T$. Neglecting all vibrational modes, calculate the total internal energy of the system. (Oxygen has two rotational modes.)

Q. Relativistic corrections become necessary when the expression for the kinetic energy $\frac{1}{2}m{v}^2$, becomes comparable with $m{c}^2$, where $m$ is the mass of the particle. At what de Broglie wavelength will relativistic corrections become important for an electron?

1. $\lambda ={10}^{-1}nm$
   
   
2. $\lambda ={10}^{-4}nm$
   
   
   
3. $\lambda =10nm$
   
   
   
4. $\lambda ={10}^{-6}nm$

Q.

The maximum number of possible interference maxima for slit-separation equal to four times the wavelength in Youngs double-slit experiment is

Q. Under similar conditions of temperature and pressure, in which of the following gases the velocity of sound will be largest?

1. $C{O}_2$
2. $N_2$
3. $H_2$
4. $He$

Q. The equation of two light waves are $y_1=6cos\omega t,y_2=8cos(\omega t+\varphi )$ the ratio of maximum to minimum intensities produced by the superposition of these wave will be

1. 49 :1
2. 1 : 49
3. 1 : 7
4. 7: 1

Q. The polarizing angle for a piece of glass for green light is ${60}^{\circ }$. Find the angle of minimum deviation for green light for its passage through ${60}^{\circ }$ prism, made of same glass.

1. ${30}^{\circ }$
2. ${15}^{\circ }$
3. ${60}^{\circ }$
4. ${45}^{\circ }$

Q. The solid angle subtended by the periphery of square of side $5\text{cm}$ at a point situated symmetrically at a distance of $10\text{cm}$ from the square is :

1. $0.5\text{steradian}$
2. $0.25\text{steradian}$
3. $1\text{steradian}$
4. $1.5\text{steradian}$

Q. The intensity ratio $\frac{I_1}{I_2}$ of the two interfering sources in Young's experiment is 4. The ratio $\frac{I_{max}}{I_{min}}$ is:

1. 4 : 1
2. 2 : 1
3. 3 : 1
4. 9 : 1

Q.

In Young double slit experiment if the maximum intensity of light is $I_{max}$ then the intensity at path difference $\frac{\lambda }{2}$
will be)

1. $I_{max}$
2. $\frac{I_{max}}{4}$
3. $zero$
4. $\frac{I_{max}}{2}$

Q. fraunhoffer diffraction simple explanation

Q. In YDSE the first bright fringe after the centre fringe is observed at P. If the screen is continuously moved away from plane of slits, then ratio of intensity at point P to intensity at point O [center of screen]

1. remains same
2. keeps on increasing
3. can become $\infty$
4. first decreases and then increases