Transverse electromagnetic wave

Longitudinal electromagnetic wave

MCQ Questions for Class 12 Medical Physics Electromagnetic Waves Quiz 4

The waves that are propagated by simultaneous periodic variations of electric and magnetic field intensity known as:

0%
Transverse wave
0%
Longitudinal wave
0%
Electromagnetic wave
0%
None of the above

Solar radiation is

0%
Transverse electromagnetic wave
0%
Longitudinal electromagnetic wave
0%
Stationary wave
0%
None of the above

In a parallel C-R network with a voltage source, the current flowing through resistor is _______ current and that flowing through the capacitor is ________ current.

0%
conduction, displacement
0%
displacement, conduction
0%
displacement, displacement
0%
conduction, conduction

The part of the electromagnetic spectrum which is suitable for radar systems used in aircraft navigation :

0%
X-Rays
0%
Gamma Rays
0%
Microwaves or short radiowaves
0%
Ultraviolet

Which scientist experimentally proved the existence of electromagnetic wave.

0%
Marconi
0%
Hertz
0%
Maxwell
0%
S.C.Bose

Explanation

Heinrich Rudolf Hertz was a German physicist, who first conclusively proved the existence of Electromagnetic waves then theorised by James clerk Maxwell.

So Hertz is the one who proved the existence of electromagnetic waves.

Therefore option

$B$ is correct.

The wavelength range of thermal radiation is

0%
from $4000\mathring { A }$ to $7000\mathring { A }$
0%
from $7700\mathring { A }$ to $4\times { 10 }^{ 6 }\mathring { A }$
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from ${10}^{6}\mathring { A }$ to ${10}^{8}\mathring { A }$
0%
from $4\times { 10 }^{ -12 }\mathring { A }$ to $4\times { 10 }^{ 8 }\mathring { A }$

Explanation

The wavelength range of thermal radiation is from

$7700\mathring{A}$ to

$4\times10^6\mathring{A}$ . Thermal radiation is the emission of electromagnetic waves from all matter that has a temperature greater than absolute zero. It represents a conversion of thermal energy into electromagnetic energy. Thermal energy consists of the kinetic energy of random movements of atoms and molecules in matter.

Electromagnetic waves are:

0%
Transverse
0%
Longitudinal
0%
May be longitudinal or transverse
0%
Neither longitudinal nor transverse

Which one of waves tans our skin and causes some substances to become fluorescent?

0%
infrared waves.
0%
ultraviolet waves.
0%
gamma rays.
0%
infrared and ultraviolet waves both.

In an electromagnetic wave

0%
Power is equally transferred along electric and magnetic fields
0%
Power is transmitted in a direction perpendicular to both the field
0%
Power is transmitted along electric field
0%
Power is transmitted along magnetic field

Explanation

For electromagnetic waves

$\vec{E}$ and

$\vec{B}$ are always perpendicular to each other and perpendicular to the direction of propagation. The direction of propagation is the direction of

$\vec{E}\times \vec{B}$ .

The direction of propagation of the wave is the direction of propagation of its energy and power.

Hence, correct answer is option B.

As speed decreases, if we change medium of electromagnetic waves from air to water, frequency

0%
also decreases.
0%
also increases.
0%
remains same.
0%
may increase or decrease.

Which one of waves cannot be seen through electromagnetic spectrum?

0%
radio waves
0%
micro waves.
0%
infrared waves.
0%
ultraviolet waves.

The waves used in telecommunication are.

0%
Infra red
0%
Ultraviolet
0%
Micro waves
0%
Cosmic rays

To distinguish between real gems and artificial gems a merchant may use which of the following radiations?

0%
Infrared rays
0%
$\gamma$ -rays
0%
X-rays
0%
Ultraviolet rays

In the order of increasing frequency, the electromagnetic spectrum may be arranged as

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Gamma rays, X-rays, visible light, radio waves
0%
X-rays, gamma rays, visible light, radio waves
0%
Radio waves, visible light, X-rays, gamma rays
0%
Radio waves, visible light, gamma rays, X-rays

A fire screen produces sensation of cooling as

0%
It allows both infrared and visible light but cuts off ultraviolet
0%
It allows infrared and cuts off shorter wavelengths
0%
It cuts off both visible light and infrared
0%
It slows only visible light and cuts off infrared

For wireless communication of voice signal through the atmosphere, we use electromagnetic waves in the_________Region of spectrum

0%
Ultraviolet
0%
Visible
0%
Microwave
0%
Radiowave

Clear images of soft tissues can be well studied using.

0%
MRI
0%
X-rays
0%
Ultrasonics
0%
I.R rays

In which one of the following regions of the electromagnetic specturm will the vibration motion of molecules give rise to absorption?

0%
Ultraviolet
0%
Microwave
0%
Infrared
0%
Radio wave

Infrared radiation was discovered in

$1800$ by :

0%
William Wallaston
0%
William Herschel
0%
Wilhelm Roentgen
0%
Thomas Young

Maximum diffraction takes place in a given slit for

0%
$\gamma$ -rays
0%
Ultraviolet light
0%
Infrared light
0%
Radio waves

Which radiations are used in treatment of muscles ache?

0%
Ultraviolet
0%
Infrared
0%
Microwave
0%
X-rays

The ozone layer is important because

0%
It prevents the cooling of each at night
0%
It prevents the IR rays coming from the space
0%
It prevents UV rays from the meteors coming from the space
0%
It prevents the UV rays and micro rays the coming from the space

The frequencies of X-rays,

$\gamma-rays$ and ultra violet rays are respectively

$p, q$ and

$r$ , then

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$p > q, q > r$
0%
$p < q, q > r$
0%
$p < q, q < r$
0%
$p > q, q < r$

Explanation

Increasing order of wavelengths as given below

$\gamma-rays < X-rays >$ ultravoilet rays
Frequency order

$\gamma-ray > X-rays >$ ultravoilet rays

$\Rightarrow q > p > r$
Thus,

$q > p$

$q > r$

$p > r$ .

The waves used by artificial satellites for communication is the

0%
microwaves
0%
infrared waves
0%
radio waves
0%
X-rays

What name is given to the type of astronomy having the following characteristics.
I. It is carried out in the waveband

$300$ nm to

$10$ nm.
II. The atmosphere is opaque to the incoming radiation from space
III. Observations are to be carried out from above the earth's atmosphere.

0%
X-ray astronomy
0%
Ultra-violet astronomy
0%
Infra-red astronomy
0%
Gamma ray astronomy

Explanation

Ultra-violet astronomy is carried out in waveband of

$10nm-300nm$ in which is above earth's atmosphere.

$X-$ ray falling on a material

0%
Exerts a force on it
0%
Transfer energy to it
0%
Transfers momentum to it
0%
Transfers impules to it

The spectrum of molecular form the substance is called :

0%
band spectrum
0%
line spectrum
0%
absorption spectrum
0%
continuous spectrum

Which one of the following is unstable

0%
$\alpha$ ray
0%
$y-ray$
0%
proton
0%
neutron

Explanation

$\alpha -ray$ is the sub atomic particles and their associated energy that are released during the decomposition of the unstable nuclei are referred to as radiation-

so that the correct option is A.

Wavelength of gamma rays are :

0%
${ 10 }^{ -10 }m$ to less than ${ 10 }^{ -14 }m$
0%
${ 10 }^{ -14 }m$ to less than ${ 10 }^{ -10 }m$
0%
${ 10 }^{ -11 }m$ to less than ${ 10 }^{ -14 }m$
0%
${ 10 }^{ -14 }m$ to less than ${ 10 }^{ -6 }m$

An electromagnetic radiation has an energy 14.4 eV. To which region of electromagnetic spectrum does it belong?

0%
Ultraviolet region
0%
Visible region
0%
X-ray region
0%
Y-ray region

Explanation

$E=\dfrac{hc}{\lambda }$

$\lambda =\dfrac{hc}{E}=\dfrac{6.626\times {{10}^{-34}}\times 3\times {{10}^{8}}}{14.4\times 1.6\times {{10}^{-19}}}=0.86\times {{10}^{-09}}$

Cosmic Rays ${{10}^{-14}}m\,\,\,to\,\,{{10}^{-12}}m$

$\gamma$ Rays ${{10}^{-12}}m\,\,\,to\,\,{{10}^{-10}}m$

$x$ Rays ${{10}^{-10}}m\,\,\,to\,\,{{10}^{-09}}m$

Ultraviolet Rays ${{10}^{-7}}m\,\,\,to\,\,\,4\times {{10}^{-7}}m$

Hence, it lies in $x$ Rays region.

Which type of waves are produced by a television remote controller?

0%
Infra-red waves
0%
Radio waves
0%
Ultraviolet waves
0%
Visible light

How do infra-red waves differ from ultraviolet waves?

0%
Infra-red waves are longitudinal
0%
Infra-red waves have a lower speed in vacuo (in a vacuum)
0%
Infra-red waves have lower frequencies
0%
Infra-red waves have smaller wavelengths

Which is having minimum wavelength ?

0%
X-rays
0%
Ultraviolet rays
0%
y - rays
0%
Cosmic rays

Explanation

Cosmic Rays ${{10}^{-14}}m\,\,\,to\,\,{{10}^{-12}}m$

$\gamma$ Rays ${{10}^{-12}}m\,\,\,to\,\,{{10}^{-10}}m$

$x$ Rays ${{10}^{-10}}m\,\,\,to\,\,{{10}^{-09}}m$

Ultraviolet Rays ${{10}^{-07}}m\,\,\,to\,\,\,4\times {{10}^{-07}}m$

Hence, Cosmic Rays have smallest wavelength.

If an electron oscillates at a frequency of

$1\ GHz$ it gives

0%
$X-$ rays
0%
Mirowaves
0%
Infrared rays
0%
None of these

Explanation

If electron oscillate with a frequency of

$1\ GHz$ , it does not radiate any energy, which corresponds a definite wavelength. It only radiate when it jump from one orbit to another orbit.

Molybdenum is used as a target element for production of X-rays because it is

0%
A heavy element and can easily absorb high velocity electrons
0%
A heavy element with a high melting point
0%
An element having high thermal conductivity
0%
Heavy and can easily deflect electrons

Explanation

Molybdenum is used as a target element for production of X-rays because

$X$ -ray tube, target must be heavy element with high melting point.

The continuous X-ray spectrum produced by an X-ray machine at constant voltage has

0%
A maximum wavelength
0%
A minimum wavelength
0%
A single wavelength
0%
A minimum frequency

Explanation

Continuous spectrum of

$X$ -rays consists of radiation of all possible wavelength range having a definite short wavelength limit

In radio theraphy, X-rays are used to

0%
Detect bone fractures
0%
Treat cancer by controlled exposure
0%
Detect heart diseases
0%
Detect fault in radio receiving circuit

When cathode rays strike a metal target of high melting point with very high velocity, then

0%
X-rays are produced
0%
Ealpha-rays are produced
0%
TV wave are produced
0%
Ultrasonic wave are produced

The most penetrating radiation out of the following is

0%
X-rays
0%
$\beta$ -ray
0%
$\alpha$ -particles
0%
$\gamma$ -ray

Explanation

Penetrating is directly proportional to the energy of radiations.

The most penetrating radiation out of the following is

$\gamma - rays$ .

For the production of X-rays, the target should be made of

0%
Steel
0%
Copper
0%
Aluminum
0%
Tungsten

When cathode rays (tube voltage

$\sim 10\ kV$ ) collide with the anode of high atomic weight then we get

0%
Positive rays
0%
$X-$ rays
0%
Gamma rays
0%
Canal rays

X-rays region lies between

0%
Short radio wave and visible region
0%
Visible and ultraviolet region
0%
Gamma rays and ultraviolet region
0%
Short radio wave and long radio wave

X-rays are produced in laboratory by

0%
Radiation
0%
Decomposition of the atom
0%
Bombardment of heigh electrons on heavy metal
0%
None of these

Which of the following represents an infrared wavelength

0%
$10^{-4}\ cm$
0%
$10^{-5}\ cm$
0%
$10^{-6}\ cm$
0%
$10^{-7}\ cm$

Explanation

Infrared ranges from

$700nm-1mm$ , i.e

$7\times 10^{-5}cm - 0.1 cm$ .

Only

$10^{-4} cm$ lies in this range.

Hence, the correct answer is option (A).

Microwaves and radio waves can propagate in vacuum.

0%
True
0%
False

Which of the following electromagnetic wave

0%
$X-$ rays and light waves
0%
Cosmic rays and sound waves
0%
Beta rays and sound waves
0%
Alpha rays and sound waves

Which of the following are not electromagnetic waves

0%
Cosmics rays
0%
Y - rays
0%
$\beta$ - rays
0%
X- rays

Explanation

$\beta$ - rays are not electromagnetic waves .

In vacuum an electrons of energy

$10\ KeV$ hits tungsten target, then emitted radiation will be

0%
Cathode rays
0%
X-rays
0%
Infrared rays
0%
Visible spectrum

Explanation

When a high energy electron incident on heavy metal, it produced

$X-$ rays.

Velocity of x-ray is

0%
$3 \times 10^6 m/sec$
0%
$3 \times 10^8 m/sec$
0%
$3 \times 10^5 m/sec$
0%
$3 \times 10^9 m/sec$

Match the following:

Wavelength	Colour
a. $450$ to $500 nm$	Red
b. $500$ to $550 nm$	Blue
c. $550$ to $600 nm$	Green
d. $650$ to $700 nm$	Yellow

0%
a-2; b-3; c-4; d-1
0%
a-1; b-2; c-3; d-4
0%
a-4; b-3; c-2; d-1
0%
a-3; b-2; c-1; d-4

CBSE Questions for Class 12 Medical Physics Electromagnetic Waves Quiz 4 - MCQExams.com

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Practice Class 12 Medical Physics Quiz Questions and Answers

CBSE Questions for Class 12 Medical Physics Electromagnetic Waves Quiz 4 - MCQExams.com

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Practice Class 12 Medical Physics Quiz Questions and Answers

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