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 contrast in the fringes in any interference pattern depends on

Answer

Fringe width

Answer

Intensity ratio of the sources

Answer

Distance between the slits

Answer

Wavelength

Question 2

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

Answer

A cylindrical wave front

Answer

An elliptical wave front

Answer

A spherical wave front

Answer

A plane wave front

Question 3

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

Answer

None of these

Question 4

4. 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

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 5

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

Answer

Velocity of different colors is different

Answer

Phase of different colors is different

Answer

Amplitude of different colors is different

Answer

Energy of different colors is different

Question 6

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

Answer

Laser rays are not absorbed

Answer

Laser rays propagate in a straight line

Answer

Laser rays are most coherent waves

Answer

Laser rays are high velocity waves

Question 7

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

Answer

Increasing gradually

Answer

None of these

Answer

Decreasing gradually

Answer

It is constant at the center

Question 8

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

Answer

In the form of a narrow beam

Answer

Electromagnetic

Answer

Incoherent

Answer

Monochromatic

Question 9

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

Answer

Polarization

Answer

Diffraction

Answer

Absorption

Answer

Transmission

Question 10

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

Answer

Same wave length with constant phase difference

Answer

Same wavelength

Answer

Same amplitude of vibration

Answer

Same amplitude and wavelength

Question 11

11. 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

Polarization

Answer

Total internal reflection of light

Answer

Interference pattern produced due to thin oil film

Question 12

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

Answer

Opposite to each other

Answer

At a far off distance

Answer

Coinciding

Answer

Close together

Question 13

13. Crystals of a material can behave as

Answer

Convex lens

Answer

Interferometer

Answer

Diffraction grating

Question 14

14. Appearance of colour in thin films is due to

Answer

Polarization

Answer

Interference

Answer

Dispersion

Answer

Diffraction

Question 15

15. 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 16

16. The fringe spacing in case of blue light

Answer

None of these

Answer

Remains the same

Question 17

17. 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 18

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

Answer

Continuous emission spectrum

Answer

Line spectrum

Answer

Emission spectrum

Answer

All of these

Question 19

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

Answer

An electromagnetic wave

Answer

A transverse waves

Answer

A longitudinal wave

Answer

A sound wave

Question 20

20. 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

Increasing the distance between the slits

Answer

Decreasing the distance between the screen and the slits

Answer

Using monochromatic light of higher frequency

Answer

Using monochromatic light of longer wavelength

Question 21

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

Answer

Wave front

Answer

Wavelength

Question 22

22. The blue colour of the sky is due to

Answer

Polarization

Answer

Reflection

Answer

Diffraction

Answer

Scattering

Question 23

23. A spherical wave front is that which has

Answer

A extended source

Answer

A point source

Answer

None of these

Question 24

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

Answer

Reflected light

Answer

Refracted light

Answer

Neither reflected nor refracted light

Answer

Both reflected and refracted light

Question 25

25. The idea of light as wave produced by

Answer

Thomos young

Question 26

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

Answer

d sin θ = m/2 λ

Answer

md cos θ = λ

Answer

d sin θ = 2λm

Answer

d sin θ = mλ

Question 27

27. Light on passing through a Polaroid is

Answer

Elliptically polarized

Answer

Plane polarized

Answer

Circularly polarized

Answer

Un-polarized

Question 28

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

Answer

None of these

Question 29

29. Diffraction fringes are

Answer

Distance between them increases

Answer

Distance between then decreases

Answer

Equally spaced

Answer

They are adjacent with no space in between

Question 30

30. Which of the following has least wavelength?

Answer

Cosmic-rays

Answer

Ultra-violet rays

Question 31

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

Answer

Wave front

Answer

A half-period zone

Question 32

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

Answer

Origin of spectra

Answer

Reflection

Answer

Diffraction

Answer

Refraction

Question 33

33. The setting of Newton’s rings is

Answer

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

Answer

A Plano convex lens and the plane glass plate

Answer

None of these

Answer

A Plano convex lens and simple glass sheet

Question 34

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

Answer

Diffraction

Answer

Origin of spectra

Answer

Refraction

Answer

Reflection

Question 35

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

Answer

Convexo-concave

Answer

Plano-convex

Answer

Plano-concave

Answer

Double-convex

Question 36

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

Answer

Huygen’s formula

Answer

Bragg’s law

Answer

Laue’s pattern

Answer

Compton effect

Question 37

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

Answer

Speed of propagation of the wave

Answer

Speed of propagation less than the wave

Answer

Speed of propagation greater than wave

Question 38

38. Intensities of the two waves of light are l and 4l. The maximum intensity of the resultant wave after superposition is

Question 39

39. Diffraction effect is

Answer

Less for a round edge

Answer

More for a sharp edge

Answer

Less for a sharp edge

Answer

More for a round edge

Question 40

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

Answer

None of these

Question 41

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

Answer

Different wavelength

Answer

Of the same frequency and having definite phase relationship

Answer

Of nearly the same frequency

Answer

Of same frequency

Question 42

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

Answer

Dark fringes are thicker than bright

Answer

None of these

Answer

Equal width

Answer

Different width

Question 43

43. Huygen’s wave theory of light cannot explain

Answer

Polarization

Answer

Photoelectric effect

Answer

Diffraction

Answer

Interference

Question 44

44. A polarizer is used to

Answer

Produce unpolarised light

Answer

Produce polarized light

Answer

Reduced intensity of light

Answer

Increase intensity of light

Question 45

45. The cause of mirage observed in desert is

Answer

Reflection

Answer

Refraction

Answer

Scattering

Answer

Total internal reflection

Question 46

46. Which one of the following cannot be polarized?

Answer

Sound waves

Answer

Radio waves

Answer

Ultraviolet rays

Question 47

47. 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 48

48. In a plane polarized light

Answer

Vibration in two mutually perpendicular directions

Answer

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

Answer

No vibration at all

Answer

Vibration in all direction

Question 49

49. 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

Interference pattern produced due to thin oil film

Answer

Total internal reflection of light

Answer

Diffraction pattern

Question 50

50. 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

Doppler’s effect

Answer

Diffraction

Answer

Interference

Question 51

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

Answer

Diffraction

Answer

Polarization

Answer

Constructive interference

Answer

Destructive interference

Question 52

52. Which of the following frequency ranges includes most of the electromagnetic waves emitted by the ultra – violet tubes used in a sun bed?

Answer

5 x 10⁵ to 5 x 10⁵ Hz

Answer

5 x 10¹¹ to 5 x 10¹⁴ Hz

Answer

5 x 10⁵ to 5 x 10¹¹ Hz

Answer

5 x 10¹⁴ to 5 x 10¹⁷ Hz

Question 53

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

Answer

Diffraction

Answer

Reflection

Answer

Polarization

Answer

Interference

Question 54

54. 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 55

55. 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 polarized

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

Question 56

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

Answer

Band emission spectrum

Answer

Line absorption spectrum

Answer

Line emission spectrum

Answer

Band absorption spectrum

Question 57

57. Light appears to travel in straight lies since

Answer

It is not absorbed by the atmosphere

Answer

Its wavelength is very small

Answer

It is reflected by the atmosphere

Answer

Its velocity is very large

Question 58

58. 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 59

59. The splitting of white light into several colors on passing through a glass prism is due to

Answer

Reflection

Answer

Refraction

Answer

Diffraction

Answer

Interference

Question 60

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

Answer

Cannot be diffracted

Answer

Do not affect a photographic plate

Answer

Have a lower frequency

Answer

Cannot be polarized

Question 61

61. Huygen’s wave theory of light cannot explain

Answer

Polarization

Answer

Interference

Answer

Diffraction

Answer

Photoelectric effect

Question 62

62. Longitudinal waves do not exhibit

Answer

Reflection

Answer

Polarization

Answer

Diffraction

Answer

Refraction

Question 63

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

Answer

Wavelength

Answer

All of these

Question 64

64. Central spot of New tons rings

Answer

Bright for large wavelength

Answer

Dart for large wavelength

Answer 217

m Sin θ = (d + 1/2)λ

Answer 218

d Sin θ = (m + 1/2)λ

Answer 219

2π Sin θ = (m + 1/2)λ

Answer 220

½ d Sin θ = mλ

Answer 221

Both dark and bright fringes are of equal width

Answer 222

Dark fringes are wider than bright fringe

Answer 223

Bright fringes are wider than dark fringes

Answer 224

Central fringes are brighter than the outer fringes

Answer 225

Ultrasonics

Answer 226

Supersonics

Answer 227

Interference with bright bands

Answer 228

Interference in which breadth of the fringe will be slightly increase

Answer 229

Interference with dark bands

Answer 230

No interference

Answer 231

Much smaller than the wavelength of length

Answer 232

Of the order of one millimeter

Answer 233

Of the same order as the wavelength of light

Answer 234

Much larger than the wavelength of light

Answer 235

Reflection

Answer 236

Refraction

Answer 237

Transmission

Answer 238

Diffraction

Answer 239

Refraction

Answer 240

Dispersion

Answer 241

Reflection

Answer 242

Interference

Answer 243

Monochromatic

Answer 244

Electromagnetic

Answer 245

Incoherent

Answer 246

In the form of a narrow beam

Answer 247

Have constant phase difference

Answer 248

Be close to each other

Answer 249

Of same amplitude

Answer 250

Wave front

Answer 251

Wavelength

Answer 252

Wave number

Answer 253

(m – 1)λ

Answer 254

d sin θ = (m + 1/2)λ

Answer 255

d sin θ = (m + 1)λ

Answer 256

d in θ = (m + ½ )1/λ

Answer 257

d sin θ = (m + 1/2)π/λ

Answer 258

Matter waves

Answer 259

Mechanical waves

Answer 260

Transverse

Answer 261

Longitudinal

Answer 262

Diffraction of light

Answer 263

Interference of light

Answer 264

Reflection of light

Answer 265

None of these

Answer 266

There is no relationship between rays and wave fronts

Answer 267

Rays are normal to wave front

Answer 268

Rays are not normal to wave front

Answer 269

Rays may be normal to wave front

Answer 270

3 x 10⁵ ms¯¹

Answer 271

3 x 10¯¹⁰ ms¯¹

Answer 272

3.1 x 10⁸ ms¯¹

Answer 273

3 x 10⁸ ms¯¹

Answer 274

Not comparable

Answer 275

None of these

Answer 276

Comparable

Answer 277

Y = (m + 1) λL/d

Answer 278

Y = (m + 1/2) λL/d

Answer 279

Y = (m + 1/2) λd/L

Answer 280

Y = (m + ½) dL/λ

Answer 281

Integral multiple of λ/2

Answer 282

Integral multiple of λ

Answer 283

Odd integral multiple of λ/2

Answer 284

Even integral multiple of λ

Answer 285

None of these

Answer 286

Partly produce interference

Answer 287

Impossible to predict

Answer 288

Colored fringes will be seen

Answer 289

No interference fringes will be seen

Answer 290

Alternate dark and bright fringes will be seen

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