The angle of deviation is the angle between the incident ray and emergent ray.
The angle of refraction inside the prism
The angle between the incident ray and the normal
The angle between the emergent ray and the prism base
2. What is angle of minimum deviation?
It is the smallest possible angle of deviation for a prism, occurring when the angle of incidence equals the angle of emergence and the ray passes parallel to the base of the prism.
It occurs when light passes undeviated through a prism
It is the angle when total internal reflection occurs
It happens only when the prism angle is 90°
3. What is dispersion?
The reflection of light at the surface of a prism
The scattering of monochromatic light
The absorption of light into a prism
The phenomenon of splitting of white light into its component colours on passing through a refracting medium.
4. What is angular dispersion?
The intensity difference between the spectral lines
The deviation of light inside a prism
The bending of all colours at the same angle
The angular separation between the two extreme colours (violet and red) in the spectrum.
5. What is dispersive power?
The speed at which light travels through a medium
The power of a prism to focus light
It is the ratio of angular dispersion to the mean deviation, representing a prism material’s ability to separate different wavelengths.
The amount of light absorbed by a prism
6. What does the formula i + i' = A + δ represent?
It relates the angle of incidence and emergence to the angle of prism and the angle of deviation.
It measures the angle between the prism faces
It calculates the refractive index of the prism
It determines the critical angle for total internal reflection
7. What does the equation r + r' = A indicate in prism optics?
It shows that the sum of the internal angles of refraction equals the prism angle.
It is used to calculate the angle of minimum deviation
It applies only to right-angled prisms
It shows the relationship between angle of incidence and deviation
8. What happens to a light ray passing through a prism?
It bends towards the base of the prism due to refraction.
It reflects back into the original medium
It travels straight through without deviation
It always bends away from the base
9. When is the deviation produced by a prism maximum?
When the angle of incidence is 45 degrees
When the ray enters perpendicularly to the surface
When the angle of incidence is 90 degrees.
At the angle of minimum deviation
10. Why is a prism set at minimum deviation for spectral analysis?
To obtain a pure spectrum by avoiding overlapping of colours.
