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. The principle of Michelson’s interferometers is

Answer

Reflection

Answer

Interference

Answer

Dispersion

Answer

Refraction

Question 2

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

Answer

Speed of propagation greater than wave

Answer

Speed of propagation of the wave

Answer

Speed of propagation less than the wave

Question 3

3. Wave front is the locus of all points in vibration are in the same

Answer

All of these

Answer

Wavelength

Question 4

4. Diffraction effect is

Answer

More for a sharp edge

Answer

More for a round edge

Answer

Less for a sharp edge

Answer

Less for a round edge

Question 5

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

Answer

Have a lower frequency

Answer

Do not affect a photographic plate

Answer

Cannot be diffracted

Answer

Cannot be polarized

Question 6

6. Choose the correct statement

Answer

There is no relationship between rays and wave fronts

Answer

Rays are normal to wave front

Answer

Rays are not normal to wave front

Answer

Rays may be normal to wave front

Question 7

7. Which of the following has least wavelength?

Answer

Ultra-violet rays

Answer

Cosmic-rays

Question 8

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

Answer

Coinciding

Answer

At a far off distance

Answer

Opposite to each other

Answer

Close together

Question 9

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

Answer

Wave front

Answer

Wavelength

Answer

Wave number

Question 10

10. In Young’s experiment, a dark fringe is observed when:

Answer

2π Sin θ = (m + 1/2)λ

Answer

½ d Sin θ = mλ

Answer

m Sin θ = (d + 1/2)λ

Answer

d Sin θ = (m + 1/2)λ

Question 11

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

Question 12

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

Answer

Diffraction

Answer

Refraction

Answer

Transmission

Answer

Reflection

Question 13

13. The condition for constructive interference of two coherent beams is that the path difference should be

Answer

Odd integral multiple of λ/2

Answer

Even integral multiple of λ

Answer

Integral multiple of λ

Answer

Integral multiple of λ/2

Question 14

14. A polarizer is used to

Answer

Produce polarized light

Answer

Reduced intensity of light

Answer

Increase intensity of light

Answer

Produce unpolarised light

Question 15

15. Coherent monochromatic light illuminates two narrow parallel slits and the interference pattern that results is observed on a screen some distance beyond the slits. Which modification increases the separation between the dark lines of the interference pattern?

Answer

Decreasing the distance between the screen and the slits

Answer

Increasing the distance between the slits

Answer

Using monochromatic light of longer wavelength

Answer

Using monochromatic light of higher frequency

Question 16

16. A point source of light placed in a homogeneous medium gives rise to

Answer

A plane wave front

Answer

An elliptical wave front

Answer

A spherical wave front

Answer

A cylindrical wave front

Question 17

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

Answer

Destructive interference

Answer

Constructive interference

Answer

Diffraction

Answer

Polarization

Question 18

18. Central spot of New tons rings

Answer

Dart for large wavelength

Answer

Bright for large wavelength

Question 19

19. Huygen’s wave theory of light cannot explain

Answer

Diffraction

Answer

Interference

Answer

Photoelectric effect

Answer

Polarization

Question 20

20. Can two head lights of car can produce interference

Answer

Partly produce interference

Answer

None of these

Question 21

21. Polarization occurs only in ________ waves

Answer

Mechanical waves

Answer

Longitudinal

Answer

Matter waves

Answer

Transverse

Question 22

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

Answer

Wavelength

Answer

Wave front

Question 23

23. Light appears to travel in straight lies since

Answer

It is reflected by the atmosphere

Answer

Its velocity is very large

Answer

Its wavelength is very small

Answer

It is not absorbed by the atmosphere

Question 24

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

Answer

Phase of different colors is different

Answer

Velocity of different colors is different

Answer

Amplitude of different colors is different

Answer

Energy of different colors is different

Question 25

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

Answer

None of these

Answer

Increasing gradually

Answer

It is constant at the center

Answer

Decreasing gradually

Question 26

26. 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

Both reflected and refracted light

Answer

Refracted light

Question 27

27. Wavelength of light of frequency 100 Hz is

Answer

2 x 10⁶ m

Answer

3 x 10⁶ m

Answer

5 x 10⁶ m

Answer

4 x 10⁶ m

Question 28

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

Answer

Of nearly the same frequency

Answer

Different wavelength

Answer

Of the same frequency and having definite phase relationship

Answer

Of same frequency

Question 29

29. The blue colour of the sky is due to

Answer

Reflection

Answer

Polarization

Answer

Scattering

Answer

Diffraction

Question 30

30. Appearance of colour in thin films is due to

Answer

Diffraction

Answer

Interference

Answer

Polarization

Answer

Dispersion

Question 31

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

Answer

d sin θ = (m + 1)λ

Answer

d sin θ = (m + 1/2)λ

Answer

d in θ = (m + ½ )1/λ

Answer

d sin θ = (m + 1/2)π/λ

Question 32

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

Answer

Impossible to predict

Answer

Alternate dark and bright fringes will be seen

Answer

Colored fringes will be seen

Answer

No interference fringes will be seen

Question 33

33. Crystals of a material can behave as

Answer

Convex lens

Answer

Interferometer

Answer

Diffraction grating

Question 34

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

Answer

Emission spectrum

Answer

All of these

Answer

Line spectrum

Answer

Continuous emission spectrum

Question 35

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

Answer

Two coherent light waves can be made to interfere

Answer

Light can be diffracted

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

Question 36

36. Diffraction fringes are

Answer

Equally spaced

Answer

Distance between then decreases

Answer

They are adjacent with no space in between

Answer

Distance between them increases

Question 37

37. 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

d sin θ = m/2 λ

Answer

md cos θ = λ

Question 38

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

Answer

None of these

Question 39

39. A spherical wave front is that which has

Answer

None of these

Answer

A point source

Answer

A extended source

Question 40

40. 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 41

41. Which of the following properties show light is transverse wave in nature?

Answer

Polarization

Answer

Reflection

Answer

Interference

Answer

Diffraction

Question 42

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

Answer

Plano-convex

Answer

Convexo-concave

Answer

Double-convex

Answer

Plano-concave

Question 43

43. Longitudinal waves do not exhibit

Answer

Refraction

Answer

Reflection

Answer

Polarization

Answer

Diffraction

Question 44

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

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 diffracted

Answer

Light can be polarized

Answer

Two coherent light waves can be made to interfere

Question 45

45. The fringe spacing in case of blue light

Answer

None of these

Answer

Remains the same

Question 46

46. 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 47

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

Answer

Diffraction

Answer

Origin of spectra

Answer

Reflection

Answer

Refraction

Question 48

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

Answer

5 x 10¯³ mm

Answer

2 x 10¯³ mm

Answer

2 x 10¯⁵ mm

Question 49

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

Answer

Laser rays propagate in a straight line

Answer

Laser rays are high velocity waves

Answer

Laser rays are most coherent waves

Answer

Laser rays are not absorbed

Question 50

50. Which one of the following cannot be polarized?

Answer

Sound waves

Answer

Ultraviolet rays

Answer

Radio waves

Question 51

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

Answer

None of these

Question 52

52. Two sources of light are coherent if they emit rays of

Answer

Same amplitude and wavelength

Answer

Same wave length with constant phase difference

Answer

Same wavelength

Answer

Same amplitude of vibration

Question 53

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

Answer

None of these

Question 54

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

Answer

Monochromatic

Answer

In the form of a narrow beam

Answer

Electromagnetic

Answer

Incoherent

Question 55

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

Question 56

56. According to the electromagnetic theory, the speed of light is approximately:

Answer

3 x 10¯¹⁰ ms¯¹

Answer

3 x 10⁸ ms¯¹

Answer

3 x 10⁵ ms¯¹

Answer

3.1 x 10⁸ ms¯¹

Question 57

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

Answer

Dark fringes are thicker than bright

Answer

Different width

Answer

Equal width

Answer

None of these

Question 58

58. If a wave can be polarized, it must be

Answer

A longitudinal wave

Answer

A transverse waves

Answer

An electromagnetic wave

Answer

A sound wave

Question 59

59. If the dark fringe is to be observed then we have relation

Answer

Y = (m + ½) dL/λ

Answer

Y = (m + 1) λL/d

Answer

Y = (m + 1/2) λd/L

Answer

Y = (m + 1/2) λL/d

Question 60

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

Answer

Reflection

Answer

Origin of spectra

Answer

Diffraction

Answer

Refraction

Question 61

61. The cause of mirage observed in desert is

Answer

Total internal reflection

Answer

Reflection

Answer

Refraction

Answer

Scattering

Question 62

62. 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 63

63. 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

Diffraction pattern

Answer

Total internal reflection of light

Answer

Polarization

Answer

Interference pattern produced due to thin oil film

Question 64

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

Answer

Line emission spectrum

Answer

Line absorption spectrum

Answer

Band emission spectrum

Answer

Band absorption spectrum

Answer 216

Ultrasonics

Answer 217

Supersonics

Answer 218

Interference with bright bands

Answer 219

Interference with dark bands

Answer 220

Interference in which breadth of the fringe will be slightly increase

Answer 221

No interference

Answer 222

No vibration at all

Answer 223

Vibration in all direction

Answer 224

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

Answer 225

Vibration in two mutually perpendicular directions

Answer 226

Polarization

Answer 227

Diffraction

Answer 228

Absorption

Answer 229

Transmission

Answer 230

Wave front

Answer 231

A half-period zone

Answer 232

Fringe width

Answer 233

Intensity ratio of the sources

Answer 234

Wavelength

Answer 235

Distance between the slits

Answer 236

Dark fringes are wider than bright fringe

Answer 237

Central fringes are brighter than the outer fringes

Answer 238

Bright fringes are wider than dark fringes

Answer 239

Both dark and bright fringes are of equal width

Answer 240

Interference of light

Answer 241

Diffraction of light

Answer 242

Reflection of light

Answer 243

None of these

Answer 244

Doppler’s effect

Answer 245

Diffraction

Answer 246

None of these

Answer 247

Interference

Answer 248

Thomos young

Answer 249

(m – 1)λ

Answer 250

Polarization

Answer 251

Diffraction

Answer 252

Interference

Answer 253

Photoelectric effect

Answer 254

A Plano convex lens and the plane glass plate

Answer 255

None of these

Answer 256

A Plano convex lens and simple glass sheet

Answer 257

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

Answer 258

In the form of a narrow beam

Answer 259

Monochromatic

Answer 260

Incoherent

Answer 261

Electromagnetic

Answer 262

Diffraction pattern

Answer 263

Interference pattern produced due to thin oil film

Answer 264

Total internal reflection of light

Answer 265

Polarization

Answer 266

None of these

Answer 267

Comparable

Answer 268

Not comparable

Answer 269

Interference

Answer 270

Diffraction

Answer 271

Reflection

Answer 272

Refraction

Answer 273

Elliptically polarized

Answer 274

Un-polarized

Answer 275

Plane polarized

Answer 276

Circularly polarized

Answer 277

Have constant phase difference

Answer 278

Be close to each other

Answer 279

Of same amplitude

Answer 280

Source of secondary wave front

Answer 281

None of these

Answer 282

Source of wave front

Answer 283

Much larger than the wavelength of light

Answer 284

Of the order of one millimeter

Answer 285

Much smaller than the wavelength of length

Answer 286

Of the same order as the wavelength of light

Answer 287

5 x 10⁵ to 5 x 10⁵ Hz

Answer 288

5 x 10⁵ to 5 x 10¹¹ Hz

Answer 289

5 x 10¹¹ to 5 x 10¹⁴ Hz

Answer 290

5 x 10¹⁴ to 5 x 10¹⁷ Hz

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:

You May Also Like

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:

You May Also Like

Latest Updates

Maan Ali

5 Comments

Leave a Reply Cancel reply