Physics Lights and Optics Online Mcqs Test

Q: How can I prepare for Physics Lights and Optics Online Mcqs Test?

You can prepare for Physics Lights and Optics Online Mcqs Test by attempting the free online quizzes at Gotest.com.pk. We provide instant results, performance reports, and detailed explanations for every question.

Question 1

1. A prism splits a beam of white light into its seven constituent colors. This is so because

Answer

Amplitude of different colors is different

Answer

Velocity of different colors is different

Answer

Energy of different colors is different

Answer

Phase of different colors is different

Question 2

2. Polarization occurs only in ________ waves

Answer

Longitudinal

Answer

Transverse

Answer

Matter waves

Answer

Mechanical waves

Question 3

3. Which of the following has least wavelength?

Answer

Cosmic-rays

Answer

Ultra-violet rays

Question 4

4. A polarizer is used to

Answer

Produce unpolarised light

Answer

Increase intensity of light

Answer

Produce polarized light

Answer

Reduced intensity of light

Question 5

5. The contrast in the fringes in any interference pattern depends on

Answer

Fringe width

Answer

Distance between the slits

Answer

Intensity ratio of the sources

Answer

Wavelength

Question 6

6. The relation of constructive interference in X-ray diffraction is called

Answer

Compton effect

Answer

Laue’s pattern

Answer

Bragg’s law

Answer

Huygen’s formula

Question 7

7. The idea of light as wave produced by

Answer

Thomos young

Question 8

8. In Michelson interferometer to switch the fringe from bright to dark the mirror should be displaced through

Question 9

9. Which one of the following phenomena is not explained by Hygen’s construction of wave front?

Answer

Reflection

Answer

Origin of spectra

Answer

Refraction

Answer

Diffraction

Question 10

10. When crest of one wave falls over the trough of the other wave this phenomenon is known as

Answer

Polarization

Answer

Constructive interference

Answer

Diffraction

Answer

Destructive interference

Question 11

11. One condition for interference is that the two sources should be coherent and:

Answer

Coinciding

Answer

At a far off distance

Answer

Close together

Answer

Opposite to each other

Question 12

12. A thin film is a transparent medium whose thickness with the wavelength of light are

Answer

None of these

Answer

Not comparable

Answer

Comparable

Question 13

13. Interference was observed in interference chamber, when air was present, now the chamber is evacuated and if the same light is used, a careful observer will see

Answer

Interference with bright bands

Answer

Interference with dark bands

Answer

No interference

Answer

Interference in which breadth of the fringe will be slightly increase

Question 14

14. Appearance of colour in thin films is due to

Answer

Polarization

Answer

Dispersion

Answer

Diffraction

Answer

Interference

Question 15

15. Which one of the following phenomena is not explained by Huygen’s construction of wave front?

Answer

Origin of spectra

Answer

Diffraction

Answer

Reflection

Answer

Refraction

Question 16

16. In the Michelson Interferometer, if m number fringes pass through a reference point when the mirror is moved a distance d, then the wavelength of the light can be found by the formula:

Answer

λ = 2π dm

Question 17

17. Light is a type of energy which produces sensation of

Answer

None of these

Question 18

18. Why laser rays are used to measure long distance?

Answer

Laser rays are not absorbed

Answer

Laser rays are most coherent waves

Answer

Laser rays propagate in a straight line

Answer

Laser rays are high velocity waves

Question 19

19. In a plane polarized light

Answer

Vibration take place in a direction perpendicular to the direction of propagation of light

Answer

Vibration in two mutually perpendicular directions

Answer

No vibration at all

Answer

Vibration in all direction

Question 20

20. Light appears to travel in straight lies since

Answer

Its wavelength is very small

Answer

It is not absorbed by the atmosphere

Answer

It is reflected by the atmosphere

Answer

Its velocity is very large

Question 21

21. Huygen’s wave theory of light cannot explain

Answer

Photoelectric effect

Answer

Interference

Answer

Polarization

Answer

Diffraction

Question 22

22. For constructive interference the path difference is

Answer

(m – 1)λ

Question 23

23. When the light is incident on polarizing angle which of the following is completely polarized?

Answer

Neither reflected nor refracted light

Answer

Reflected light

Answer

Refracted light

Answer

Both reflected and refracted light

Question 24

24. Crystals of a material can behave as

Answer

Interferometer

Answer

Convex lens

Answer

Diffraction grating

Question 25

25. Choose the correct statement

Answer

Rays are normal to wave front

Answer

Rays may be normal to wave front

Answer

There is no relationship between rays and wave fronts

Answer

Rays are not normal to wave front

Question 26

26. The phenomenon of bending of light waves around the edges of an obstacle or a narrow opening is called.

Answer

Transmission

Answer

Refraction

Answer

Diffraction

Answer

Reflection

Question 27

27. The blue colour of the sky is due to

Answer

Diffraction

Answer

Reflection

Answer

Polarization

Answer

Scattering

Question 28

28. The locus of all points in the same phase of vibration is called:

Answer

Wave number

Answer

Wave front

Answer

Wavelength

Question 29

29. Which effect provides direct experimental evidence that light is a transverse, rather than a longitudinal, wave motion?

Answer

Light can be polarized

Answer

The intensity of light from a point source falls off inversely as the square of the distance from the source

Answer

Two coherent light waves can be made to interfere

Answer

Light can be diffracted

Question 30

30. To demonstrate the phenomenon of interference we require two sources that emit radiation

Answer

Of nearly the same frequency

Answer

Of the same frequency and having definite phase relationship

Answer

Different wavelength

Answer

Of same frequency

Question 31

31. Which one of the following cannot be polarized?

Answer

Sound waves

Answer

Ultraviolet rays

Answer

Radio waves

Question 32

32. On a rainy day, if there is an oil drop on tar road, colored rings are seen around this drop. This is because of

Answer

Total internal reflection of light

Answer

Interference pattern produced due to thin oil film

Answer

Polarization

Answer

Diffraction pattern

Question 33

33. According to Huygen, every point on a wave front may be regarded as a __________ of secondary wavelets.

Question 34

34. If the path difference must be half-integral number wavelength

Answer

d sin θ = (m + 1/2)π/λ

Answer

d in θ = (m + ½ )1/λ

Answer

d sin θ = (m + 1)λ

Answer

d sin θ = (m + 1/2)λ

Question 35

35. Curtain less windows are made by making use of __________ of light.

Answer

Absorption

Answer

Transmission

Answer

Polarization

Answer

Diffraction

Question 36

36. The locus of all points in a medium having the same phase of vibration is called

Answer

Wave front

Answer

Wavelength

Question 37

37. In the phenomenon of interference, the bright ad dark fringes are of

Answer

None of these

Answer

Equal width

Answer

Dark fringes are thicker than bright

Answer

Different width

Question 38

38. Every point of a wave front may be considered as a

Answer

Source of wave front

Answer

Source of secondary wave front

Answer

None of these

Question 39

39. A diffraction grating has 500 lines per mm. Its slit spacing or grating element will be equal to

Answer

2 x 10¯³ mm

Answer

2 x 10¯⁵ mm

Answer

5 x 10¯³ mm

Question 40

40. A spectrum which contains all wavelengths without any break is called

Answer

Line spectrum

Answer

Emission spectrum

Answer

Continuous emission spectrum

Answer

All of these

Question 41

41. When the two surfaces of a thin film are parallel and the light is incident at a certain angle, _________ fringes are formed.

Answer

Elliptical

Question 42

42. If a source of light is moving away from stationary observer, then frequency of light wave appears to change because of

Answer

None of these

Answer

Diffraction

Answer

Interference

Answer

Doppler’s effect

Question 43

43. Huygen’s wave fronts which sends out secondary wavelets with a speed equal to

Answer

Speed of propagation less than the wave

Answer

Speed of propagation of the wave

Answer

Speed of propagation greater than wave

Question 44

44. Diffraction effect is

Answer

Less for a round edge

Answer

Less for a sharp edge

Answer

More for a round edge

Answer

More for a sharp edge

Question 45

45. Which of the following is conserved when light waves interfere?

Question 46

46. Ultra – violet rays differ from X-rays in that ultra – violet rays

Answer

Do not affect a photographic plate

Answer

Cannot be polarized

Answer

Cannot be diffracted

Answer

Have a lower frequency

Question 47

47. An oil surface floating on water surface exhibits beautiful colour patter, which is due to

Answer

Diffraction of light

Answer

None of these

Answer

Interference of light

Answer

Reflection of light

Question 48

48. The principle of Michelson’s interferometers is

Answer

Interference

Answer

Dispersion

Answer

Refraction

Answer

Reflection

Question 49

49. The light produced by a laser is all the following except

Answer

Electromagnetic

Answer

Monochromatic

Answer

In the form of a narrow beam

Answer

Incoherent

Question 50

50. Fraunhoffer’s lines commonly visible in the sun’s spectrum are examples of

Answer

Line absorption spectrum

Answer

Band absorption spectrum

Answer

Line emission spectrum

Answer

Band emission spectrum

Question 51

51. Which effect provides direct experimental evidence that light is a transverse, rather than a longitudinal, wave motion?

Answer

Light can be diffracted

Answer

Two coherent light waves can be made to interfere

Answer

The intensity of light from a point source falls off inversely as the square of the distance from the source

Answer

Light can be polarized

Question 52

52. In Young double slit experiment, if white light is used

Answer

Alternate dark and bright fringes will be seen

Answer

Colored fringes will be seen

Answer

Impossible to predict

Answer

No interference fringes will be seen

Question 53

53. The light produced by a laser is all the following except

Answer

Incoherent

Answer

Monochromatic

Answer

Electromagnetic

Answer

In the form of a narrow beam

Question 54

54. In Huygen’s wave theory, the locus of all points in the same state of vibration is called

Answer

A half-period zone

Answer

Wave front

Question 55

55. The fringe spacing in case of blue light

Answer

Remains the same

Answer

None of these

Question 56

56. Due to Plano convex lens and the plane glass plate the thickness of air film changes from the center to outward

Answer

Decreasing gradually

Answer

Increasing gradually

Answer

It is constant at the center

Answer

None of these

Question 57

57. The setting of Newton’s rings is

Answer

A Plano convex lens and simple glass sheet

Answer

None of these

Answer

A Plano convex lens and the plane glass plate

Answer

A Plano convex lens (long focal length) and the plane of glass plate

Question 58

58. Longitudinal waves do not exhibit

Answer

Reflection

Answer

Diffraction

Answer

Polarization

Answer

Refraction

Question 59

59. Who devise the experimental arrangement is 1801 for studying interference effects of light?

Answer

None of these

Question 60

60. The condition for the bright fringes formed due to constructive interference in a diffraction grating is:

Answer

d sin θ = mλ

Answer

d sin θ = 2λm

Answer

md cos θ = λ

Answer

d sin θ = m/2 λ

Question 61

61. On a rainy day, if there is an oil drop on tar road, colored rings are seen around this drop. This is because of

Answer

Polarization

Answer

Diffraction pattern

Answer

Interference pattern produced due to thin oil film

Answer

Total internal reflection of light

Question 62

62. A ____________ lens is used to form Newton’s rings.

Answer

Plano-concave

Answer

Plano-convex

Answer

Convexo-concave

Answer

Double-convex

Question 63

63. In Newton’s rings the point of contact of the lend and the glass plate, the air film is

Answer

None of these

Question 64

64. For the sustained interference of light, the necessary condition is that the two sources should

Answer

Of same amplitude

Answer

Have constant phase difference

Answer

Be close to each other

Answer 208

Bright fringes are wider than dark fringes

Answer 209

Central fringes are brighter than the outer fringes

Answer 210

Dark fringes are wider than bright fringe

Answer 211

Both dark and bright fringes are of equal width

Answer 212

4 x 10⁶ m

Answer 213

3 x 10⁶ m

Answer 214

2 x 10⁶ m

Answer 215

5 x 10⁶ m

Answer 216

m Sin θ = (d + 1/2)λ

Answer 217

2π Sin θ = (m + 1/2)λ

Answer 218

d Sin θ = (m + 1/2)λ

Answer 219

½ d Sin θ = mλ

Answer 220

A cylindrical wave front

Answer 221

An elliptical wave front

Answer 222

A spherical wave front

Answer 223

A plane wave front

Answer 224

3.1 x 10⁸ ms¯¹

Answer 225

3 x 10¯¹⁰ ms¯¹

Answer 226

3 x 10⁸ ms¯¹

Answer 227

3 x 10⁵ ms¯¹

Answer 228

Diffraction

Answer 229

Polarization

Answer 230

Photoelectric effect

Answer 231

Interference

Answer 232

Un-polarized

Answer 233

Plane polarized

Answer 234

Circularly polarized

Answer 235

Elliptically polarized

Answer 236

Wavelength

Answer 237

All of these

Answer 238

Same wave length with constant phase difference

Answer 239

Same amplitude of vibration

Answer 240

Same wavelength

Answer 241

Same amplitude and wavelength

Answer 242

Partly produce interference

Answer 243

None of these

Answer 244

5 x 10⁵ to 5 x 10¹¹ Hz

Answer 245

5 x 10¹¹ to 5 x 10¹⁴ Hz

Answer 246

5 x 10¹⁴ to 5 x 10¹⁷ Hz

Answer 247

5 x 10⁵ to 5 x 10⁵ Hz

Answer 248

Refraction

Answer 249

Reflection

Answer 250

Interference

Answer 251

Diffraction

Answer 252

Y = (m + 1) λL/d

Answer 253

Y = (m + 1/2) λL/d

Answer 254

Y = (m + ½) dL/λ

Answer 255

Y = (m + 1/2) λd/L

Answer 256

A point source

Answer 257

None of these

Answer 258

A extended source

Answer 259

Using monochromatic light of longer wavelength

Answer 260

Using monochromatic light of higher frequency

Answer 261

Decreasing the distance between the screen and the slits

Answer 262

Increasing the distance between the slits

Answer 263

Ultrasonics

Answer 264

Supersonics

Answer 265

A sound wave

Answer 266

A transverse waves

Answer 267

An electromagnetic wave

Answer 268

A longitudinal wave

Answer 269

Dart for large wavelength

Answer 270

Bright for large wavelength

Answer 271

Integral multiple of λ/2

Answer 272

Odd integral multiple of λ/2

Answer 273

Even integral multiple of λ

Answer 274

Integral multiple of λ

Answer 275

They are adjacent with no space in between

Answer 276

Equally spaced

Answer 277

Distance between then decreases

Answer 278

Distance between them increases

Answer 279

Much smaller than the wavelength of length

Answer 280

Of the same order as the wavelength of light

Answer 281

Of the order of one millimeter

Answer 282

Much larger than the wavelength of light

Answer 283

Diffraction

Answer 284

Polarization

Answer 285

Interference

Answer 286

Reflection

Answer 287

Scattering

Answer 288

Reflection

Answer 289

Refraction

Answer 290

Total internal reflection

Total Questions:	88
Time Allowed:	40 Minutes
Total Marks:	88
How to Attempt Test:	Please choose the right Option in MCQ-type question.
Test Helpful For:	Physics Test ECAT Test MDCAT Test FPSC/PPSC/SPSC/KPPSC/BPSC/AJKPSC/NTS Physics Interview Question Answer

Physics Lights and Optics Online Mcqs Test

Important Lights and Optics Question and Answer

Physics Lights and Optics Practice Test Online With Explanation

Physics

How to Score High in Physics Lights and Optics Online Mcqs Test?

Key Preparation Tips:

More Related Resources

Maan Ali

5 Comments

Leave a Reply Cancel reply

Important Lights and Optics Question and Answer

Physics Lights and Optics Practice Test Online With Explanation

Physics

How to Score High in Physics Lights and Optics Online Mcqs Test?

Key Preparation Tips:

More Related Resources

Latest Updates

Maan Ali

5 Comments

Leave a Reply Cancel reply