FSC Physics MCQs Chapter 15 Class 12

Created on February 07, 2022

Physics Ch 15 Class 12 Electromagnetic Waves

1 / 65

When interference between thin films occurs, the path difference between two interfering rays is 2t. If ‘n’ is the refractive index of the medium, the bright circles are obtained when ________ with m = 0, 1, 2, 3, …

NUMS 2019 Reconduct
Physics
Electromagnetic Waves
Elimination Tool:

A) (2m + 1) λ = 4nt

B) (2m + 1) λ = 2nt

C) 2m = nt

D) mλ = 2nt

2 / 65

A common material for cushioning objects in packages is made by trapping bubbles of air between sheets of plastic. Is this material more effective at keeping the contents of the package from moving around inside the package?

PMC Practice 8
Physics
Electromagnetic Waves
Elimination Tool:

A) A hot day

B) A cold day

C) Either hot or cold days

D) There is not enough information to say

3 / 65

Choose the correct arrangement of the various regions of the electromagnetic spectrum in terms of wave length.

ETEA 2017
Physics
Electromagnetic Waves
Elimination Tool:

A) Ir>uv> visible > microwave > radio frequency

B) Microwave >ir> visible >uv> radio frequency

C) Radio frequency > microwave >ir> visible >uv

D) Visible >ir>uv> microwave > radio wave

4 / 65

Microwave is:

2022 PMC Test 3
Physics
Electromagnetic Waves
Elimination Tool:

A) An electromagnetic wave

B) Sound wave

C) Longitudinal wave

D) Standing wave

5 / 65

Rays produced by LED are:

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Ultraviolet

B) Visible light

C) Infrared

D) All of these

6 / 65

Which of the following statements is True about the A.0 and D.0 Generators?

Slip Rings for A.C and Split rings for D.C

Split rings for AC and Slip Rings for D.C

Either Slip rings for A.C or Split rings for D.C

Either Split rings for A.C or Slip rings for D.C

7 / 65

Beta rays cannot be stopped by:

PMC Practice 11
Physics
Electromagnetic Waves
Elimination Tool:

A) Paper

B) Water

C) Air

D) All of these options are correct

8 / 65

A stationary wave is formed in a pipe which is open at one end. If length of pipe is L, then what is the maximum possible wavelength of the wave.?

PMC Practice 20
Physics
Electromagnetic Waves
Elimination Tool:

A) L

B) 2L

C) 3L

D) 4L

9 / 65

Polarization of light shows that it is:

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Magnetic in nature

B) None of these

C) Electric in nature

D) Both

10 / 65

What will be the energy stored In an inductor of length 2m if a current of 10A passes through it

10J

100J

200J

50J

11 / 65

The direct exposure of sun light where ozone layer is depleted will cause:

2022 PMC Test 1
Physics
Electromagnetic Waves
Elimination Tool:

A) Skin cancer

B) Sugar

C) Corona

D) Sun burn

12 / 65

Which of the following is CORRECT for photons?

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) E= hv

B) E = h/cλ

C) P = h/λ

D) E = mc

13 / 65

A coil is placed near a magnet. Emf will be induced in it when

Area of coil is changed

Coil is rotated

Magnet which was placed at a distance is moved closer to it.

All of these

14 / 65

Which of the following statement is true? i) Toroid is a solenoid bent into circular path ii) Solenoid is a tarok’ in open

i is true

ii is true

Both a and b

None of these

15 / 65

A changing electric field produces

emf

Changing magnetic field

Current

None of these

16 / 65

Germanium and silicon are semiconductors having crystalline structures. Both these materials have ______ valence electrons in their outermost shells.

NTS 2014
Physics
Electromagnetic Waves
Elimination Tool:

A) 2

B) 4

C) 6

D) 8

17 / 65

Applications of laser is/are:

NTS 2011
Physics
Electromagnetic Waves
Elimination Tool:

A) to perform precision surveying and length measurements

B) as a potential energy source for including nuclear fusion reactions

C) for telephone communications along optical fibers

D) for precision cutting of metals and other materials

E) all of these

18 / 65

A sound wave travels from a region of hot air into a region of cold air. How does frequency and wavelength of sound change?

PMC Practice 21
Physics
Electromagnetic Waves
Elimination Tool:

A) Frequency decreases wavelength decreases

B) Frequency increases wavelength decreases

C) Frequency does not change as wavelength decreases

D) Frequency does not change wavelength does not change

19 / 65

Sound waves are:

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Both

B) Neither

C) Transverse

D) Longitudinal

20 / 65

Unit of induced emf is

Volts

Ampere

Newton

Joule

21 / 65

The wave in which crest and trough superimpose each other is ?

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Sound wave

B) Light wave

C) Stationary wave

D) All of these

22 / 65

Induced emf depends upon:

v

B

Magnetic force

All of these

23 / 65

A D.C generator is converted in A.C generator by

Increasing the rings

Replacing split rings by slip rings

none

Decreasing the rings

24 / 65

A tuning fork A produces 4 beats with another tuning fork B. if the frequency of tuning fork B is 320 Hz, then the frequency of tuning fork A is:

PMC Practice 21
Physics
Electromagnetic Waves
Elimination Tool:

A) 320 * 4

B) 320 / 4

C) 320+4

D) 320

25 / 65

Which electrical quantity cannot be changed by a transformer?

Voltage

Current

Power

Inductance

26 / 65

Extraterrestial waves are also called:

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Alpha rays

B) Cosmic rays

C) Gamma rays

D) Beta rays

27 / 65

The direction of induced emf is given by which of the following law?

Faraday law

Lenz law

Ampere law

None

28 / 65

In microwave ovens ____ is used to heat the food

PMC Practice 33
Physics
Electromagnetic Waves
Elimination Tool:

A) X-rays

B) Beta rays

C) Gamma rays

D) Electromagnetic rays

29 / 65

The light we see is:

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) None of these

B) Infrared

C) Visible

D) Ultraviolet

30 / 65

Energy emitted in the form of visible radiation is called:

2022 PMC Test 1
Physics
Electromagnetic Waves
Elimination Tool:

A) Light energy

B) Sound energy

C) Tidal energy

D) Geothermal energy

31 / 65

Which one of the following waves needs a medium to travel?

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) X rays

B) Gamma rays

C) None of these

D) Beta rays

32 / 65

If Ns/Np is the turn ratio, then for step up transformer

Ns > Np

Ns = Np

Ns < Np

None

33 / 65

If the current flow increases to 100 times, the energy stored in the inductor will increase to:

100 times

1,000 times

10,000 times

Remains same

34 / 65

A.C generator can be converted into D.0 generator by

Slip rings

Split rings

Stopper

Cannot be converted

35 / 65

Electric Generators work on the principle of:

Coulomb's law

Newton's law of gravitation

Ampere's law

Electromagnetic Induction

36 / 65

Longitudinal standing wave, in second harmonic mode, is established in a tube that is open at both ends. The length of the tube is 0.8m. What is the wavelength of the waves that make up the standing wave?

PMC Practice 10
Physics
Electromagnetic Waves
Elimination Tool:

A) 0.20m

B) 0.40m

C) 0.80m

D) 1.60m

37 / 65

Which of the following phenomenon proves that light waves are transverse waves?

PMC Practice 4
Physics
Electromagnetic Waves
Elimination Tool:

A) Polarization

B) Refraction

C) Interference

D) Diffraction

38 / 65

Characteristic x-rays are produced by:

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Photons

B) All of these

C) Electrons

D) Protons

39 / 65

An electromagnetic wave travels in a straight line through a vacuum. The wave has a frequency of 6.0 THz. What is the number of wavelengths in a distance of 1.0 m along the wave?

ETEA 2018
Physics
Electromagnetic Waves
Elimination Tool:

A) 5.0 × 10–5

B) 2.0 × 101

C) 2.0 × 104

D) 5.0 × 107

40 / 65

Which one of the following requires no medium?

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Beta rays

B) Alpha rays

C) Gamma rays

D) All of these

41 / 65

In single slit diffraction, when wavelength lameda increases:

PMC Practice 20
Physics
Electromagnetic Waves
Elimination Tool:

A) Width of central maxima increases

B) Width of central maxima does not change

C) Central maxima becomes brighter

D) Width of central maxima decreases

42 / 65

Which of the following is not major application of electromagnetic induction

T.V

Radio

Transformer

Telephone

43 / 65

Microwaves are _______ waves.

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Tranverse

B) Electromagnetic

C) Longitudinal

D) Transverse and electromagnetic

44 / 65

potential difference in charge between two points in a circuit is known as?

Emf

Electric difference

Intensity

Volt

45 / 65

Electromagnetic waves are produced by:

NTS 2012
Physics
Electromagnetic Waves
Elimination Tool:

A) Motion of electric and magnetic fields

B) Chargeless particles

C) A static charge

D) Heat

46 / 65

Michelson’s interferometer works on the principle of:

PMC Practice 21
Physics
Electromagnetic Waves
Elimination Tool:

A) Interference of light

B) Refraction of light

C) Reflection of light

D) Diffraction of light

47 / 65

Polarization explains light is ———

PMC Practice 8
Physics
Electromagnetic Waves
Elimination Tool:

A) Electric in nature

B) Magnetic in nature

C) Both A and B

D) None of these

48 / 65

The region that lies between IR and UV regions is called:

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Radio waves

B) None of these

C) X ray region

D) Visible light

49 / 65

Which rays are used in LASER?

PMC 2021 Tested
Physics
Electromagnetic Waves
Wave Motion and Sound
Elimination Tool:

A) Electromagnetic radiation

B) Black body radiation

C) Alpha rays

D) Beta rays

50 / 65

A star moving away from earth shows:

PMC Practice 21
Physics
Electromagnetic Waves
Elimination Tool:

A) Green shift

B) Red shift

C) Blue shift

D) None of these

51 / 65

The distance between two consecutive nodes is:

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Half a wavelength

B) Two wavelengths

C) One-fourth the wavelength

D) One wavelength

52 / 65

Orange light in a vacuum has a wavelength of 600 nm. What is the frequency of this light?

ETEA 2018
Physics
Electromagnetic Waves
Elimination Tool:

A) 180 Hz

B) 5.0 × 105 Hz

C) 1.8 × 1011 Hz

D) 5.0 × 1014 Hz

53 / 65

In medical scanning, which rays are used?

PMC Practice 18
Physics
Electromagnetic Waves
Elimination Tool:

A) Photon

B) X

C) Beta

D) White

54 / 65

X-rays are used to measure?

PMC Practice 8
Physics
Electromagnetic Waves
Elimination Tool:

A) Fractures

B) Temperature

C) Blood pressure

D) All of these

55 / 65

Transformer cannot step up

DC voltage

AC voltage

None of these

Both a and b

56 / 65

Infrasonic waves have a frequency of:

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Greater than 20000 Hz

B) Less than 20 Hz

C) 20 Hz

D) Greater than 20 Hz

57 / 65

When a conductor moves In magnetic field the Induced emf Is

Motional

Rotational

Transferal

All of these

58 / 65

Torsion balance is used to measure:

Spring constant

Electric force

Gravitational constant

All

59 / 65

Which list shows electromagnetic waves in order of increasing frequency?

ETEA 2018
Physics
Electromagnetic Waves
Elimination Tool:

A) radio waves → gamma rays → ultraviolet → infra-red

B) radio waves → infra-red → ultraviolet → gamma rays

C) ultraviolet → gamma rays → radio waves → infra-red

D) ultraviolet → infra-red → radio waves → gamma rays

60 / 65

When carrying electricity on long distances. Step up transformer are used to:

Increase both voltage and current

Increase voltage reduce current

Increase current reduce voltage

None of these

61 / 65

In water pipes, ____ is used to detect leakages.

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Light

B) Radiation

C) Current

D) None of these

62 / 65

The electromagnetic radiation which moves with high frequency will have _______ wavelength:

2022 PMC Test 3
Physics
Electromagnetic Waves
Elimination Tool:

A) Short

B) Long

C) Unchanged

D) Variable

63 / 65

Resistance opposes current, inductor opposes

Current

Change in current

emf of a battery

All

64 / 65

Which of the following does not travel in vacuum?

PMC 2021 Tested
Physics
Electromagnetic Waves
Elimination Tool:

A) Transverse waves

B) Radio waves

C) Sound waves

D) Light rays

65 / 65

Which of the following is not E.M wave?

ETEA 2019
Physics
Electromagnetic Waves
Elimination Tool:

A) Radio waves

B) X-rays

C) Light waves

D) Sound waves

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