Total Internal Reflection

Q.

The refractive index of a diamond is 2.42. What is the meaning of this statement?

Q. Explain why the planets do not twinkle? :-)

Q.

Light enters at an angle of incidence in a transparent rod of refractive index n. For what value of the refractive index of the material of the rod the light once entered into it will not leave it through its lateral face whatsoever be the value of the angle of incidence

1. 
2. 
3. 
4. 

Q.

State the condition for total internal reflection.

Q.

The incident ray, reflected ray, and the outward drawn normal are denoted by the unit vectors$\overrightarrow{a},\overrightarrow{b}$ and $\overrightarrow{c}$. Respectively. Then choose the correct relation for these vectors.

1. $\overrightarrow{b}=2\overrightarrow{a}+\overrightarrow{c}$

2. $\overrightarrow{b}=\overrightarrow{a}-\overrightarrow{c}$

3. $\overrightarrow{b}=\overrightarrow{a}+2\overrightarrow{c}$

4. $\overrightarrow{b}=\overrightarrow{a}-2\left(\overrightarrow{a·}\overrightarrow{c}\right)\overrightarrow{c}$

Q.

In an optical fibre, the refractive index of the core should be lesser than the refractive index of the cladding.

1. False

2. True

Q.

A disc is placed on the surface of a pond which has a refractive index $\frac{5}{3}$. A source of light is placed $4m$ below the surface of a liquid. Find the minimum radius of a disc so that light does not come out from the disc?

Q.

What is Snells law for reflection and refraction?

Q.

An astronaut in outer space will observe the sky as:

1. White

2. Black

3. Blue

4. Red

Q. Explain refractive index with example using sin I by sin r??

Q. A ray of light from denser medium strikes a rarer medium. The reflected and refracted rays make an angle of 90 degree with each other. The angles of reflection and refraction are r and r. The critical angle would be

Q.

What does the eye within a triangle radiating light mean in French Revolution?

Q. Does light travel at different speeds in different mediums?

Q.

Why does a light ray incident on a rectangular glass slab immersed in any medium emerges parallel to itself? Explain using a diagram.

Q. The cause of hypermetropia is a/an in focal length of the eye lens and of the eyeball.

1. increase
2. decrease
3. shortening
4. elongation

Q.

What is an optical transmitter? Give an example.

Q.

Explain the term critical angle with the aid of a labeled diagram.

Q.

Which color of light has a higher critical angle? Red light or Green light.

Q.

What is the principle of fiber optical communication?

1. Total internal reflection

2. Refraction

3. Dispersion

4. Coherence

Q.

A light ray from the air is incident (as shown in the figure) at one end of a glass fiber (refractive index $\mu$ = 1.5) making an incidence angle of ${60}^{\circ }$ on the lateral surface so that it undergoes a total internal reflection. How much time would it take to traverse the straight fiber of length 1 km

Time taken by light to traverse some distance in a medium $t=\frac{\mu x}{c}$

1. 5.77 μ sec
2. 3.85 μ sec
3. 3.33 μ sec
4. 6.67 μ sec

Q.

Difference between ADS panel and IPS panel in LED TV?

Q.

The refractive index of diamond in much greater than that of ordinary glass. Is this fact of some use to a diamond-cutter?

Q.

Find the angle between the emergent ray and incident ray when the light goes from air to glass slab.
Given ${\mu }_{glass}=1.5$

1. 180°

2. 300°

3. 0°

4. 60°

Q.

The critical angle between an equilateral prism and air is 45°. If the incident ray is perpendicular to the refracting surface as shown below, then

1. After deviation, it will emerge from the BC refracting side

2. It is totally reflected from the BC and AC refracting sides and finally emerges out from the AB side

3. It is totally reflected from all the three sides of prism and never emerges out

4. It is totally reflected on the BC and emerges out perpendicularly from the AC side in air

Q.

The advantage of optical fiber is

1. High bandwidth and EM interference

2. Low bandwidth and EM interference

3. High bandwidth, low transmission capacity, and no EM interference

4. High bandwidth, high data transmission capacity and no EM interference

Q. For total internal reflection to occur, the minimum value for angle of refraction $r$ is equal to____.

1. ${180}^{\circ }$
   
2. ${90}^{\circ }$
3. ${360}^{\circ }$
4. ${150}^{\circ }$

Q.

The optical path length is equal to _____?

Q.

A ray of light is incident at an angle of ${45}^{\circ }$ on a square slab of a transparent material. What should be the refractive index of the material of the slab so that total internal reflection occurs at the vertical face AB?

1. $\sqrt{2}$

2. $\sqrt{\frac{5}{3}}$

3. $\sqrt{\frac{3}{2}}$

4. $1.5$

Q. In total internal reflection, the angle of incidence is ___ the critical angle.

1. greater than
2. equal to
3. less than
4. independent of

Q. Define refractive of a transparent medium