Modern Physics: MCQ Test (50 questions)

Question 1 of 50

The recently discovered high temperature superconductor is-

Apure rare earth metal
BInorganic polymer
CCeramic Oxide
DMetal Alloys

Question 2 of 50

An isotope of an atomic nucleus is that nucleus in which-

AThe number of neutrons is the same, but the number of protons is different
BThe number of protons is the same, but the number of neutrons is different.
CThe number of both protons and neutrons remains the same.
DBoth protons and neutrons have different numbers.

Question 3 of 50

The age of the oldest style group is estimated.

AIn the K-Ar method
Bby the uranium-lead method
CBy Ra-Si method
DC 14by method

Question 4 of 50

The process of splitting of a heavy nucleus into two lighter nuclei is called-

Anuclear fusion
Bnuclear fission
Cradioactive disintegration
DMass damage

Question 5 of 50

Who discovered the positron?

ARutherford
BThomson
CChadwick
DAnderson

Question 6 of 50

What is the mass number of an element whose atom has two protons, two neutrons and two electrons?

A2
B4
C6
D8

Question 7 of 50

'Laser' is a device which is produced by-

Aspontaneous radiation
BDispersed radiation
Cscattered radiation
DStimulated radiation

Question 8 of 50

When the TV is switched on, then-

ABoth audio and video start simultaneously
BThe audio is played immediately, but the visual is played later, as the scene requires some practice time.
CThe visuals begin immediately, but the audio is heard later because sound travels slower than light.
DIt depends on the brand of the TV.

Question 9 of 50

How do stars get their energy?

Aas a result of nuclear fusion
Bfrom nuclear fission
Cby chemical reaction
Dby gravitational pull

Question 10 of 50

Which of the following types of radiation has the shortest wavelength?

Aradio waves
Bvisible light
CInfrared
DUltraviolet

Question 11 of 50

Diode is a device which allows current to

Aallows flow in one direction
BAllows flow in both directions
CDoes not allow flow in any direction
Dnone of the above

Question 12 of 50

Carries electrons-

Aone unit negative charge
Bone unit positive charge
Ctwo units of negative charge
Dtwo units of positive charge

Question 13 of 50

Which of the following metals is used as a semiconductor in transistors?

ACopper
BGermanium
Cgraphite
DSilver

Question 14 of 50

Photoelectric effect is explained as the ejection of electrons from the metal surface under which condition?

Amay it get warm
BIt is placed in a strong electric field
CElectrons of suitable velocity collide with it.
Dlight of appropriate wavelength falls on it

Question 15 of 50

Which type of electromagnetic radiation is used for remote control of television?

AInfrared
BUltraviolet
CScene
Dnone of the above

Question 16 of 50

Isotopes are atoms of the same element that have

ASame atomic weight but different atomic number
BDifferent atomic weights but same atomic number
CBoth atomic mass and atomic number are the same.
Dnone of the above

Question 17 of 50

Which of the following has a negative charge?

AX-rays
Ba - particle
CB particles
Dy-particle

Question 18 of 50

Which one of the following is not a property of X-rays?

AThey are deflected by electric fields
BThey are not deflected by magnetic fields.
CTheir penetration length in matter is high.
DIt has a much shorter wavelength than visible light.

Question 19 of 50

X-rays are used to study crystal structure because-

AThe crystal completely absorbs X-rays.
BThe wavelength of X-rays and the interatomic distance of the crystal are of the same order of magnitude.
CX-rays have very small wavelengths, comparable to the interatomic distances of a crystal.
DThe crystal is completely transparent to X-rays.

Question 20 of 50

Who treats stones without surgery?

AX-ray
Bpleuroscopy
CLaser
Dultrasound

Question 21 of 50

The principle of atomic bomb is based on—

Aon nuclear fusion
Bon nuclear fission
Con both of the above
Dnone of these

Question 22 of 50

Protons reside in the atom-

Awithin the nucleus
Boutside the nucleus
Cin the orbital
Dboth in the nucleus and in the orbitals

Question 23 of 50

The temporary particle in the following is-

AProton
Belectron
CNeutron
Dalpha particles

Question 24 of 50

What is photoelectric effect?

Ainstantaneous process
Bdelayed process
CEmission of protons
DNeutron emission

Question 25 of 50

At what temperature can superconductivity be of great economic importance, leading to savings of millions of rupees?

Aat extremely low temperatures
BThe temperature at which it becomes a semiconductor
Cat normal temperature
Dat extremely high temperatures

Question 26 of 50

'Super conductors' are substances which are-

Awhich offers the least resistance to the flow of electric current
Bwhich conduct electricity at low temperatures
Cwhich conduct electricity at high temperatures
DWhich provide high resistance to the flow of electric current.

Question 27 of 50

Which one of the following is not a property of X-rays?

AThey are deflected by electric fields
BThey are not deflected by magnetic fields.
CTheir penetration length in liquid is large.
DTheir wavelength is much shorter than that of visible light.

Question 28 of 50

What can X-rays be used for?

ADetecting gold underground
BDetecting heart disease
CDetection of flaws in precious stones and diamonds
Dcutting and welding metal

Question 29 of 50

Match List-I with List-II and select the correct answer using the code given below the lists. List-I (Radioisotopes) List-II (Diagnostic uses) A. Arsenic-74 1. Hyperactivity of thyroid gland B. Cobalt 60 2. Blood disorders C. Iodine-131 3. Tumor D. Sodium-24 4. Cancer

AABCD 1 2 3 4
BABCD 4 3 1 2
CABCD 3 4 1 2
DABCD 4 3 2 1

Question 30 of 50

The energy of the sun is produced by-

Aby ionization
Bby nuclear fusion
Cby oxidation
Dby oxidation

Question 31 of 50

Cryogenic engines are used in—

Ain the rocket
Bin a nuclear reactor
Cin frosted refrigerators
Din research on superconductivity

Question 32 of 50

Barium is fed to patients in a suitable form before abdominal X-ray examination because-

ABarium allows X-rays to pass through the stomach due to its transparency to X-rays.
BVarium compounds, like magnesium sulfate, help clear the stomach before X-ray examinations.
CBarium is a good absorber of X-rays and this helps the stomach (compared to other areas) to be seen more clearly in the image.
DBarium salts are white in color and this helps the stomach to be seen more clearly in the image than other areas.

Question 33 of 50

When two p and p type semiconductors are brought into contact, the pn junction they form acts as?

Aamplifier
BDriver
Coscillator
Drectifier

Question 34 of 50

What is radar used for?

Adetection of submerged submarines
BReceiving signals from a radio receiver
CIdentifying distant objects and detecting energy
Dlocating the satellite

Question 35 of 50

Whose conclusion is the mass energy relation?

Aquantum theory
Bgeneral theory of relativity
CField theory of energy
DSpecial theory of relativity

Question 36 of 50

The following principle works in the atomic bomb:

Anuclear fusion
Bnuclear fission
CFleming's Law
Dphotoelectric effect

Question 37 of 50

Find the number of protons in the nucleus of a hydrogen atom.

AZero
BOne
CThree
Dfive

Question 38 of 50

Due to what is the huge amount of energy released in the explosion of an atomic bomb?

Aconversion of matter into energy
Bconversion of chemical energy into heat energy
Cconversion of mechanical energy into nuclear energy
Dconversion of neutrons into protons

Question 39 of 50

Hydrogen bomb is based on-

Aon nuclear fusion
Bon nuclear fission
Con all of the above
Don all of the above

Question 40 of 50

The electron was discovered by-

AThomson
BJames Watt
CGalileo
DRutherford

Question 41 of 50

Einstein was awarded the Nobel Prize for-

Afor photoelectric effect
BFor the theory of specific heats
CFor the special theory of relativity
Dfor Bose-Einstein statistics

Question 42 of 50

Heavy water (D) in nuclear reactors2In what form is O used?

Adiluent
Bcoolant
Cpreservative
Dcontroller

Question 43 of 50

Atoms having the same atomic number but different atomic masses are called-

Aisobar
Bisotopes
CIsobars
DNone of these

Question 44 of 50

Otto Hahn discovered the atomic bomb on the basis of the following principle:

Auranium fission
Bnuclear fission
Calpha radiation
Dgamma radiation

Question 45 of 50

Which of the following is used as a neutron moderator in a nuclear reactor?

Aheavy water
Bgraphite
CCadmium
Daluminium

Question 46 of 50

The resistance of a semiconductor when heated is-

Aincreases
Bdecreases
Cremains the same
DFirst increases and then decreases. (e) None of the above / More than one of the above

Question 47 of 50

Television signals cannot be received beyond a certain distance because-

AThe signs are weak
BThe antenna is weak
Cabsorbs air signals
Dthe surface of the earth is curved

Question 48 of 50

In the production of X-rays-

Aproduction of X-rays
Bnuclear fission in practice
Cthermonuclear fusion in operation
DIn nuclear acceleration

Question 49 of 50

Which of the following statements is not correct regarding ultraviolet light?

AIt is an electromagnetic wave
BIts wavelength is smaller than that of visible light.
Cit is a longitudinal wave
DIt can move in vacuum

Question 50 of 50

What is the Coolidge tube used to produce?

Aradio waves
Bmicrowaves
CX-rays
Dgamma rays