Maxima & Minima in YDSE

Q.

In Young's double slit experiment using two identical slits, the intensity of the maximum at the centre of the screen is I. What will be the intensity at the centre of the screen if one of the slits is closed?

1. I

2. $\frac{I}{2}$

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

4. None of these

Q.

Light of wavelengths $\lambda$ is incident on a slit of width d. The resulting diffraction pattern is observed on a screen at a distance D. The linear width of the principal maximum is equal to the width of the slit if D equals

1. $\frac{d}{\lambda }$

2. $\frac{2\lambda }{d}$

3. $\frac{d^2}{2\lambda }$

4. $\frac{2{\lambda }^2}{d}$

Q. The two slits in Young's interference experiment have widths in the ratio n:1. The ratio of the intensities of the maxima and minima in the interference pattern is

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

Q.

Light of wavelengths $\lambda$ is incident on a slit of width d. The resulting diffraction pattern is observed on a screen at a distance D. The linear width of the principal maximum is equal to the width of the slit if D equals

1. $\frac{d}{\lambda }$

2. $\frac{2\lambda }{d}$

3. $\frac{d^2}{2\lambda }$

4. $\frac{2{\lambda }^2}{d}$

Q. In Young's double slit experiment, the fringes are formed at a distance of $1\text{m}$ from double slit of separation $0.12\text{mm}$. Given $\lambda =6000\stackrel{\circ }{A}$. Then the distances of 3rd dark band from the centre of the screen and 3rd bright band from the centre of the screen will be respectively

1. $1.25\text{cm},1.5\text{cm}$
2. $2.25\text{cm},2.5\text{cm}$
3. $3.25\text{cm},3.5\text{cm}$
4. $0.25\text{cm},0.5\text{cm}$

Q.

In young's double slit experiment, the two slits act as coherent sources of equal amplitude A and of wavelength $\lambda .$ In another experiment with the same set up, the two slits are sources of equal amplitude A and wavelength $\lambda$ but are incoherent. The ratio of the intensity of light at the midpoint of the screen in the first case of that in the second case is

1. 1:1

2. 1:2

3. 2:1

4. $\sqrt{2}:1$

Q. The figure below shows the path of white light’s rays which leave in phase from two small sources $S_1$ and $S_2$ and travel to a point X on a screen. The path difference is $S_{2}X-S_{1}X=8.7\times {10}^{-7}m$. What wavelength of light gives complete destructive interference at X?

1. $4.0\times {10}^{-7}m$
2. $4.4\times {10}^{-7}m$
3. $6.6\times {10}^{-7}m$
4. $5.8\times {10}^{-7}m$

Q. Young's double-slit experiment is carried with two thin sheets of thickness $10.4\mu m$ each and refractive index ${\mu }_1=1.52$ and ${\mu }_2=1.40$ covering the slits $S_1$ and $S_2$ respectively. If white light of range $400\text{nm}$ to $780\text{nm}$ is used, then which wavelength will form maxima at point $O$, the center of the screen?

1. $416\text{nm}$ only
2. $624\text{nm}$ only
3. $416\text{nm}$ and $624\text{nm}$ only
4. None of these

Q. The figure below shows the path of white light’s rays which leave in phase from two small sources $S_1$ and $S_2$ and travel to a point X on a screen. The path difference is $S_{2}X-S_{1}X=8.7\times {10}^{-7}m$. What wavelength of light gives complete destructive interference at X?

1. $4.0\times {10}^{-7}m$
2. $4.4\times {10}^{-7}m$
3. $6.6\times {10}^{-7}m$
4. $5.8\times {10}^{-7}m$

Q.

While light is used to illuminate the two slits in Young's double slit experiment. The separation between the slits is d and the distance between the screen and the slit is D (>> d). At a point on the screen directly in front of one of the slits, certain wavelengths are missing. The missing wavelengths are (here m=0, 1, 2, .....is an integer)

1. $\frac{d^2}{(2m+1)D}$

2. $\frac{(2m+1)d^2}{D}$

3. $\frac{d^2}{(m+1)D}$

4. $\frac{(m+1)d^2}{D}$

Q. In YDSE distance between the slits and screen is $1.5\text{m}$. When light of wavelength $500\text{nm}$ is used, the $2^{nd}$ bright fringe is obtained on the screen at a distance of $10\text{mm}$ from the central bright fringe. What will be shift in position of $2^{nd}$ bright fringe, if light of wavelength $550\text{nm}$ is used ?

1. $2\text{mm}$
2. $1\text{mm}$
3. $1.5\text{mm}$
4. $1.1\text{mm}$