JOIN ADRE 2.0 Telegram Group

MCQ On Class 12 Physics Chapter 8 Electromagnetic Waves

Questions
1 The waves used by artificial satellites for communication is
A microwaves
B infrared waves
C radio waves
D X-rays

Answer:microwaves
2 A charged particle oscillates about its mean equilibrium position with a frequency of 109 Hz. The frequency of electromagnetic waves produced by the oscillator is
A 106 Hz
B 107 Hz
C 108 Hz
D 109 Hz

Answer:109 Hz
Advertisement
Article and Schedule Quiz Start Test!

DOWNLOAD CURRENT AFFAIRS PDF FROM APP

3 Which of the following has/have zero average value in a plane electromagnetic wave?
A Both magnetic and electric fields
B Electric field only
C Magnetic field only
D None of these

Answer:Both magnetic and electric fields
4 Which of the following statement is false for the properties of electromagnetic waves?
A Both electric and magnetic field vectors attain the maxima and minima at the same place and same time.
B The energy in electromagnetic waves is divided equally between electric and magnetic field vectors
C Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of wave.
D These waves do not require any material medium for propagation.

Answer:Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of wave.
5 If a variable frequency ac source is connected to a capacitor then with decrease in frequency the displacement current will
A increase
B decrease
C remains constant
D first decrease then increase

Answer:decrease
6 Maxwell in his famous equations of electromagnetism introduced the concept of
A ac current
B displacement current
C impedance
D reactance

Answer:displacement current
7 The ultra high frequency band of radio waves in electromagnetic wave is used as in
A television waves
B cellular phone communication
C commercial FM radio
D both (a) and (c)

Answer:cellular phone communication
8 An electromagnetic wave can be produced, when charge is
A moving with a constant velocity
B moving in a circular orbit
C falling in an electric field
D both (b) and (c)

Answer:both (b) and (c)
9 Which of the following electromagnetic waves is used in medicine to destroy cancer cells?
A IR-rays
B Visible rays
C Gamma rays
D Ultraviolet rays

Answer:Gamma rays
10 The conduction current is same as displacement current when source is
A ac only
B dc only
C either ac or dc
D neither dc nor ac

Answer:either ac or dc
11 Ampere’s circuital law was modified by:
A Laplace
B Gauss
C Maxwell
D Hertz

Answer:Maxwell
12 Choose the wrong statement?
A Electromagnetic waves are transverse
B Electromagnetic waves travel with the speed of light in free space
C Electromagnetic waves are produced by accelerating charges
D Electromagnetic waves travel with the same speed in all media

Answer:Electromagnetic waves travel with the same speed in all media
13 The existence of EMW was experimentally established by :
A Sir S. C. Bose
B Maxwell
C Marconi
D Hertz

Answer:Sir S. C. Bose
14 The dimensions of E/Bare same as that of:
A charge
B current
C velocity
D acceleration

Answer:velocity
15 EMW are produced by:
A charge in uniform motion only
B charge at rest only
C accelerated or decelerated charge only
D all of the above

Answer:accelerated or decelerated charge only
16 Displacement current is due to:
A the flow of electrons
B the Varying electric field
C the ionization of atmosphere
D the flow of protons

Answer:the Varying electric field
17 Choose the wave relevant to telecommunication :
A ultraviolet
B infrared
C microwave
D visible light

Answer:microwave
18 Displacement current is always :
A equal to conduction current
B less than conduction current
C greater than conduction current
D the sum of current due to flow of positive and negative ions

Answer:equal to conduction current
19 Which of the following EMW has highest wavelength?
A X-ray
B ultraviolet rays
C infrared rays
D microwaves

Answer:infrared rays
20 Which of the following laws was modified by Maxwell by introducing the displacement current?
A Gauss’s law
B Ampere’s law
C Biot-Savart’s law
D None of theseL

Answer:Ampere’s law

ADRE 2.0 FULL LENGTH MOCK TEST

Take Mock Tests

Missiles Mock Test Start Test!
SSC MTS Mock Test Start Test
IBPS CLERK MOCK TEST Start Test
SSC MTS 2022 JULY 26 Shift 1 (ENGLISH) Start Test!
SSC GD Previous Year Paper 2021 Nov 17 Shift - I (Hindi) Start Test!
SSC CGL Tier - 1 PYP 2022 April 21 Shift- 1 (ENGLISH) Start Test!
MPSC PAPER I MOCK TEST 1 (ENGLISH) Start Test!
IB Security Assistant Mock test 1 (english) Start Test!
UP POLICE CONSTABLE MOCK TEST 1 Start Test!
DELHI POLICE CONSTABLE MOCK TEST 1 (HINDI) Start Test!

Chapters

Advertisement
Assam Direct Recruitment Test Series