Lateral Displacement

Q. A beam of light is converging towards a point I on a screen. A plane glass plate whose thickness in the direction of the beam = t, refractive index =$\mu$ , is introduced in the path of the beam. The convergence point is shifted by

1. 
2. 
3. 
4. 

Q. In the figure, the optical fiber is $2m$ long and has a diameter $d=20\mu m$. If a ray of light is incident on one end of the fiber at angle ${\theta }_1={40}^{\circ }$, the number of reflections it makes before emerging from the other end is close to (refractive index of fiber is $1.31$ and $sin{40}^{\circ }=0.64$)

1. 66000
2. 55000
3. 45000
4. 57000

Q. Two parallel rays are travelling in a medium of refractive index ${\mu }_1=\frac{4}{3}$. One of the rays passes through a parallel glass slab of thickness t and refractive index ${\mu }_2=\frac{3}{2}$. The path difference between the two rays due to the glass slab will be

1. $\frac{t}{8}$
2. $\frac{4t}{3}$
3. $\frac{3t}{2}$
4. $\frac{t}{6}$

Q.

In a thin prism of glass (refractive index $1.5$), which of the following relations between the angle of minimum deviation ${\delta }_m$ and angle of refraction $r$ will be correct ?

Q. A monochromatic beam of light is incident at ${60}^o$ on one face of an equilateral prism of refractive index $n$ and emerges from the opposite face making an angle $\theta \left(n\right)$ with the normal. For $n=\sqrt{3}$ the value of $\theta$ is ${60}^o$ and $\frac{d\theta }{dn}=m$. The value of $m$ is

Q. In a Fraunhofer diffraction experiment, a single slit of width $0.5mm$ is illuminated by a monochromatic light of wavelength $600nm$. The diffraction pattern is observed on a screen at a distance of $50cm$ from the slit. What will be the linear separation of the first order minima?

1. $1.0mm$
2. $1.1mm$
3. $0.6mm$
4. $1.2mm$

Q. On a hot summer night, the refractive index of air is minimum near the ground and increase with height from the ground. When a light beam is directed horizontally, the Huygen's principle leads us to conclude that as it travels, the light beam

1. becomes narrower
2. goes horizontally without any deflection
3. bends downwards
4. bends upwards

Q.

A light ray is incident at an angle of ${45}^{\circ }$ with the normal to a $\sqrt{2}\text{cm}$ thick plate $(\mu =2.0)$. Find the shift in the path of the light as it emerges out from the plate.

Q.

A diverging beam of light from a point source S having divergence angle a, falls symmetrically on a glass slab as shown. The angles of incidence of the two extreme rays are equal. If the thickness of the glass slab is t and the refractive index n, then the divergence angle of the emergent beam is

1. Zero

2. a

3. 

4. 

Q. A solid glass sphere of radius 10 cm that has a small air bubble O trapped at a dis†an ce 4 cm from the centre C. The refractive index of the material of glass is 1.8. The apparent position of the bubble from surface where it will appear, when seen through the surface of the sphere from an outside point is a)-4.54 cm b)-2.54 cm c)-1.24 cm d)-6.24 cm

Q. The position and velocity of a point object $A$ at a given instant of time are as shown. At that instant, considering the refraction through lens,

1. The image is located on the principal axis at a distance of $40\text{cm}$ from lens.
2. The speed of the image is $\sqrt{30}{\text{cms}}^{-1}$ w.r.t lens.
3. The velocity components for image w.r.t lens are $2{\text{cms}}^{-1}$ along -ve X axis and $6{\text{cms}}^{-1}$ along -ve Y axis respectively.
4. The velocity components for image w.r.t lens are $6{\text{cms}}^{-1}$ along -ve X axis and $2{\text{cms}}^{-1}$ along -ve Y axis respectively

Q.

Figures 9.34(a) and (b) show refraction of a ray in air incident at 60° with the normal to a glass-air and water-air interface, respectively. Predict the angle of refraction in glass when the angle of incidence in water is 45º with the normal to a water-glass interface [Fig. 9.34(c)].

Q. A prism of angle $A=1^{\circ }$ has a refractive index $\mu =1.5$. A good estimate for minimum angle of deviation (in degrees) is close to $\frac{N}{10}$. Value of $N$ is

Q.

A ray of light going from denser to rarer medium suffers refraction at a concave surface. Which of the following relations is correct?

1. 

2. 

3. 

4. 

Q. A small air bubble is inside a glass cube of side 15cm.when seeing from the top face, the bubble appears at a distance of 5cm and if seen from the opposite face it appears at 7cm.Refractive index of glass

Q. In a double slit experiment, the distance between the two slits is $0.6\text{mm}$ and these are illuminated with light of wavelength $4800\mathring{A}$. The angular width of dark fringe on the screen at a distance $120\text{cm}$ from slits will be,

1. $8\times {10}^{-4}\text{rad}$
2. $6\times {10}^{-4}\text{rad}$
3. $4\times {10}^{-4}\text{rad}$
4. $16\times {10}^{-4}\text{rad}$

Q. A thin prism of angle $A=6^{\circ }$ produces minimum deviation of ${\delta }_{min}=3^{\circ }$. Find the refractive index of the material of the prism.

1. $1.33$
2. $1.53$
3. $1.5$
4. $1.41$

Q. The magnification produced by an astronomical telescope when the final image is formed at infinity is $10$ and the length of the telescope is $1.1\text{m}$. The magnification when the final image is formed at least distance of distinct vision is -

1. $10$
2. $12$
3. $14$
4. $16$

Q.

A monochromatic light of $\lambda =500A^{\circ }$ is incident on two identical slits separated by a distance of $5\times {10}^{-4}\text{m}$. The interference pattern is seen on a screen placed at a distance of $1\text{m}$ from the plane of slits. A thin glass plate of thickness $1.5\times {10}^{-6}\text{m}$ and refractive index $\mu =1.5$ is placed between one of the slits and the screen. Find the intensity at the center of the slit now.

Q. Determine the apparent shift in the position of the coin.

1. 
   $2.5\text{cm}$
2. $2\text{cm}$
3. $1.5\text{cm}$
4. $3.5\text{cm}$

Q. In a young's double slit experiment, the first maxima is observed at a fixed point $\text{P}$ on the screen. Now the screen is continuously moved away from the plane of slits. The ratio of intensity at point $\text{P}$ to the intensity at point $\text{O}$ (center of the screen) is-

1. Remains constant
2. Keeps on decreasing
3. First decreases and then increases
4. First decreases and then becomes constant

Q. A glass sphere (refractive index =1.5) with a radius of 15cm has a tiny air bubble 5cm above its centre. The sphere is viewed looking down along the extended radius containing the bubble. What is the apparent depth of the bubble below the surface of the sphere?

Q. 121.A air bubble inside a glass slab appears to be 6cm deep when viewed from one side and 4cm deep when viewed from the opposite side. If refractive index of glass is 1.5, then the thickness of the slab is?

Q. In a young’s double slit experiment, $D$ equals the distance of screen and $d$ is the separation between the slit. The distance of the nearest point to the central maximum where the intensity is same as that due to a single slit, is equal to

1. $\frac{D\lambda }{d}$
2. $\frac{D\lambda }{2d}$
3. $\frac{D\lambda }{3d}$
4. $\frac{2D\lambda }{d}$

Q. A ray of light when incident upon a prism suffers a minimum deviation of ${39}^{\circ }.$ If the shaded half portion of the prism is removed, then the same ray will be-

1. Suffer a deviation of ${19.5}^{\circ }$
2. Suffer a deviation of ${78}^{\circ }$
3. Not suffer any deviation
4. Will be totally internally reflected

Q. unpolarised light is incident from air on a plane surface of a material of refractive index u. at a particular angle of incidence i it is found that the reflected and refracted rays are perpendicular to each other. then electric field vector is parallel or perpendicular to the plane of incidence ?

Q. Why there is no dispersion of logli through a rectangular glass slab?

Q. An air bubble in a glass slab with refractive index $1.5$ (near normal incidence) is $5\text{cm}$ deep when viewed from one surface and $3\text{cm}$ deep when viewed from the opposite face. The thickness (in $\text{cm}$) of the slab is

1. $8$
2. $10$
3. $12$
4. $16$

Q. A beam of light propagates through a medium $1$ and falls onto another medium $2$ at an angle ${45}^{\circ }$. After that, it propagates in medium $2$ at an angle ${30}^{\circ }$. The light's wavelength in medium $1$ is $141.4\dot{A}.$ Wavelength has the light in medium 2 in Angstorms is

Q. A slab of glass of thickness of $3$ units and refractive index $\sqrt{3}$ is surrounded by vacuum and is placed as shown. A light ray is incident at the point $(2,5\sqrt{3})$ as shown. The point where the ray will cut the $X-$ axis is:

1. $(6,0)$
2. $(5+\sqrt{3},0)$
3. $(9,0)$
4. $(8,0)$