Light: Reflection from Plane Mirrors and Refractive Index
Covers light reflection from plane mirrors, refractive index calculations between different media, and the principle of reversibility in optics
Questions
A plane mirror is in a vertical plane and is rotating about a vertical axis at 100 mm horizontal beam of light is incident on the mirror. The reflected beam will rotate at
- $100 rpm$
- $141 rpm$
- $0 rpm$
- $200 rpm$
When a mirror is rotated through an angle, the reflected ray moves through double that angle, the instrument based on the above principle is :
- Periscope
- Odometer
- Refractometer
- Sextant
A source of light lies on the angle bisector of two plane mirrors inclined at an angle $\theta$. The values of $\theta$, so that the light reflected from one mirror does not reach the other mirror will be
- $\theta \geq 120^0$
- $\theta \geq 90^0$
- $\theta \leq 120^0$
- $\theta < 30^0$
The angle between the incident and reflected rays is $90^o$. If the plane mirror is rotated by $10^o$ about O in the anti-clockwise direction in the plane perpendicular to the mirror, then the angle between the incident and reflected rays will be _______$^0$.
- 70
- 100
- 90
- 110
- 80
When a plane mirror is rotated through an angle $\theta$, the reflected ray rotates through an angle $2\theta$. Then the size of the image
- is halved
- is doubled
- remains unchanged
- is quadrupled
If refraction index of glass with respect to air is $ _{a}{u} _{g} = \dfrac{3}{2}$, the refraction index of air with respect to glass will be $ _{g}{u} _{a} =$
- ${3}/{2}$
- ${2}/{3}$
- ${1}/{3}$
- ${1}/{2}$
The refractive index of water with respect to air is $ _{a}{u} _{w}$ and of glass with respect to air is $ _{a}{u} _{g}$. Express the refractive index of glass with respect to water
- $\dfrac{ _{a}{u} _{g}}{ _{a}{u} _{w}}$
- $\dfrac{ _{g}{u} _{a}}{ _{a}{u} _{w}}$
- $\dfrac{ _{a}{u} _{w}}{ _{a}{u} _{g}}$
- $\dfrac{ _{a}{u} _{a}}{ _{g}{u} _{g}}$
At ray of light is incident in medium 1 at an angle of $37^{o}$ and gets refracted in medium 2 at an angle of $53^{o}$. What will be angle of refraction if light is incident in medium 2 at an angle of $53^{o}$.
- $37^{o}$
- $53^{o}$
- $36^{o}$
- $45^{o}$
When a ray of light enters a medium of refractive index $\mu $ from air. It is observed that the angle of refraction is half the angle of incidence. The angle of incidence is :
- $2 cos^{-1}(\frac{\mu }{2})$
- $ cos^{-1}(\frac{\mu }{2})$
- $2 cos^{-1}(\mu )$
- $2 sin^{-1}(\frac{\mu }{2})$
Refractive index of diamond with respect to glass is $1.6$ and absolute refractive index of glass is $1.5$. Find out the absolute refractive index of diamond.
- $1.06$
- $0.93$
- $2.4$
- $0.75$
The refractive index of water is $\dfrac{4}{3}$ and of glass is $\dfrac{3}{2}$. What will be the refractive index of glass with respect to water?
- $9.1$
- $2.623$
- $1.125$
- $1$
Principle of reversibility holds true for
- Reflection
- Refraction
- Reflection and Refraction
- None of these
Principle of reversibility can applied to
- Lens system
- Mirror system
- Lens and mirror system
- None of these
The refractive index of gias with respect to air is $3/2$ and that of water with respect to air is $4/3$. What is the refractive index of glass with respect to water?
- $9 : 8$
- $1 : 2$
- $2 : 1$
- $8 : 9$