Physics · Science General

Optics and Light Properties

2,019 Questions

Optics and light properties focus on the behavior of light, including reflection, refraction, dispersion, and polarization. This topic also covers the wave nature of light, illumination, and the functioning of optical instruments like microscopes. Questions on these concepts are common in general science sections of SSC, Railways, and State exams.

Reflection and mirrorsRefraction and mediumsLight wave theoriesPolarization and intensity

Optics and Light Properties Questions

Multiple choice perceive colours resolution of optical instruments lenses option c: imaging physics

When a beam of light is used to determine the position of an object, the maximum accuracy is achieved if the light is.

  1. Polarised

  2. Of longer wavelength largest

  3. Of shorter wavelength

  4. Of high intensity
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The resolving power of an instrument depends upon the wave length of light used. The lower the wavelength of light higher is the accuracy in vision.
$\left(Resolving\, power \,\alpha \frac{1}{\lambda}\right)$

Multiple choice perceive colours resolution of optical instruments lenses option c: imaging physics

If the refractive indices of a prism for red, yellow and violet colours be 1.61, 1.63 and 1.65 respectively, then the dispersive power of the prism will be:

  1. $\dfrac { 1.65-1.62 }{ 1.61-1 }$
  2. $\dfrac { 1.62-1.61 }{ 1.65-1 }$
  3. $\dfrac { 1.65-1.61 }{ 1.63-1 }$
  4. $\dfrac { 1.65-1.63 }{ 1.61-1 }$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Dispersive power of the prism=$\dfrac{\mu _v-\mu _r}{\mu _y-1}=\dfrac{1.65-1.61}{1.63-1}$

Multiple choice physics bharat and science scope and progress of physics recent advancement in medical technology contribution of physics in technology and society

Electron microscope is based on which scientific principle?

  1. Light amplification by stimulated emission of radiation

  2. Wave nature of electrons

  3. Digital logic

  4. Reflection of ultrasonic waves
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Electron microscope is based on the principle of De-Broglie hypothesis of wave-nature of electrons.

Multiple choice kirchoff's laws black body radiation heat transfer thermal properties physics

Statement-1:Good reflectors are poor emitters of thermal radiation.
Statement-2:The ratio of the emissive power (e) and absorptive power(a) is constant for all substances at any given temperture and for radiation of the same wavelength

  1. Statement-1 is true, Statement-2 is true and Statement-2 is the correct explanation for Statement- 1

  2. Statement-1 is true, Statement-2 is true but Statement-2 is not the correct explanation for Staement-1

  3. Statement-1 is true, Statement-2 is false.

  4. Statement-1 is false, Statement-2 is true.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

From the krichoff's law we know that absorptivity is equal to emissivity,so the body which emitt more wil absorbe more nor reflect more. So good reflector are poor emittor.
Now, by taking there ratio it validate krichoff's law because at any fixed or constant temperature both are equal.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

Three right angied prisms of refractive indices $\mu _1$,$\mu _2$ and $\mu _3$ are joined together so that the faces of the middle prism are each in contact with one the outside prism.If the ray passes through the composite block undeviated,then

  1. ${\mu _1}^2+{\mu _3}^2-{\mu _2}^2 = 1$
  2. ${\mu _1}^2-{\mu _3}^2+{\mu _2}^2 = 1$
  3. ${\mu _1}^2-{\mu _3}^2-{\mu _2}^2 = 1$
  4. ${\mu _2}^2+{\mu _3}^2-{\mu _1}^2 = 1$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For a ray to pass through a composite block of three prisms undeviated, the net deviation must be zero. This condition leads to the relationship between the refractive indices of the prisms.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

An equilateral prism deviates a ray through $45^{\circ}$ for the two angles of incidence differing by $20^{\circ}.$ The angle of incidence is

  1. $62.5^{\circ}$
  2. $42.5^{\circ}$

  3. Both are correct

  4. Both are wrong
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

First angle of incidence $=i _1=i$

Second angle of incidence $i _2=i _1+20^\circ$
Angle of deviation, $d=i _1+i _2-A$ where A is angle of prism.
$45=2i+20-60$
$i=42.5$
$i _2=i+20=62.5$
Hence both are correct.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

A ray of light is incident at an angle of $60^{\circ}$ on one face of a prism of angle $30^{\circ}$. The emergent ray of right makes an angle of $30^{\circ}$ with incident ray. The angle made by the emergent ray with second face of prism will be

  1. $0^{\circ}$
  2. $90^{\circ}$
  3. $45^{\circ}$
  4. $30^{\circ}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using the prism formula for deviation, the angle of emergence can be calculated. Given the incident angle and prism angle, the geometry confirms the emergent ray is parallel to the second face or at a specific angle.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

A right-angled prism is set to deviate a ray of light through $90^o$ . If the same prism is to be used for deviating through $180^o$ , the prism must be turned from the previous set position through the angle :

  1. $45^o$
  2. $90^o$
  3. $135^o$
  4. $180^o$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A right-angled prism deviates light by 90 degrees when light enters one leg and exits the hypotenuse. To achieve 180 degrees, the prism must be rotated to reflect the light back along its original path.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

Two thin prisms are combined to form an achromatic combination.For prism I, $  A=4^{0}, \mu _{R}=1.35, \mu _{Y}=1.40, \mu _{\nu}=1.42 .  $ For prism II $  \mu _{R}=1.7, \mu _{\gamma}=1.8  $ and $  \mu _{R}=1.9 .  $ Find the prism angle of prism II and the net mean deviation.

  1. $ 0.44^{\circ} $
  2. $ 0.45^{\circ} $
  3. $ 0.48^{\circ} $
  4. $ 0.46^{\circ} $
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Achromatic combinations require the dispersive powers to cancel out. Using the formula (omega1 * A1) + (omega2 * A2) = 0, we can solve for the unknown prism angle.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

When light rays are incident on a prism at an angle of $45^o$, the minimum deviation is obtained. If the refractive index of the material of the prism is $\sqrt 3$, then the angle of prism will be

  1. $2 \times {\sin ^{ - 1}}\frac{1}{{\sqrt 6 }}$
  2. $45^o$
  3. $60^o$
  4. $90^o$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

At minimum deviation, the angle of incidence i = (A + delta_m) / 2. Given i = 45 and mu = sqrt(3), we use the prism formula mu = sin((A+delta_m)/2) / sin(A/2) to solve for A.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

The angle of minimum deviation produced by an equilateral prism is $46^0$. The refractive index of material of the prism.

  1. 1.6

  2. 1.5

  3. 1.4

  4. 1.8
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For an equilateral prism, A = 60 degrees. Using the formula mu = sin((A + delta_m) / 2) / sin(A / 2) with delta_m = 46 degrees, we find mu = sin(53) / sin(30) = 0.8 / 0.5 = 1.6.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

The dispersive powers of flint glass and crown glass are $0.053$  and $0.034 $and respectively and their mean refractive indices are $1.68 $ and $1.53$for white light. Calculate the angle of the flint prism required to form an achromatic combination with a crown glass of refracting angle $4^0$

  1. $2^0$
  2. $4^0$
  3. $5^0$
  4. $6^0$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For an achromatic combination, the condition is omega1 * A1 + omega2 * A2 = 0. Substituting the given dispersive powers and the angle of the crown glass prism allows solving for the flint glass prism angle.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

The refractive index of a prism is 2. The prism can have a maximum refracting angle of

  1. $90^o$
  2. $60^o$
  3. $45^o$
  4. $30^o$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Critical angle of the prism such that it does not refract back into the prism from the emerging side $=\theta _c=sin^{-1}(\dfrac{1}{\mu})=sin^{-1}\dfrac{1}{2}=30^{\circ}$


The angles made by the ray inside the prism cannot be greater than $30^{\circ}$.


$A=r _1+r _2$

If $A>60^{\circ}$, the ray does not emerge from the prism. So maximum refracting angle can be $60^{\circ}$.