Modern Physics: MCQ Test (25 questions)

Question 1 of 25

The electron was discovered by-

AThomson
BJames Watt
CGalileo
DRutherford

Question 2 of 25

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 3 of 25

Cobalt-60 is commonly used in radiation therapy because it emits-

Aalpha rays
BVita Rays
Cgamma rays
DX-rays

Question 4 of 25

Stars obtain their energy from- 1. Nuclear fusion 2. Gravitational contraction 3. Chemical reaction 4. Nuclear fission

A1 and 2
B1, 2 and 3
C1 and 4
D2 and 4

Question 5 of 25

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 6 of 25

Two elements having different number of electrons but same mass number are called-

Aisotopes
Bisobar
Cisomer
Dsumneutronic

Question 7 of 25

Which element has the most isotopes?

AUranium
BRadium
Chydrogen
DCesium

Question 8 of 25

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 25

Consider the following statements: Assertion (A) Ernest Rutherford stated before the Royal Society that nuclear power would never be available to mankind. Reason (R) He believed that Einstein's law would fail and matter would not be converted into energy. Select your level from the coding scheme given below:

ABoth A and R are true and R is the correct reason
BBoth A and R are true, but R is not the correct reason
CA is true, but R is false.
DA is false, but R is true

Question 10 of 25

emits radioactive substances.

Aalpha rays
Bbeta rays
Cgamma rays
DAll of the above

Question 11 of 25

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

Aamplifier
BDriver
Coscillator
Drectifier

Question 12 of 25

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 13 of 25

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 14 of 25

Who discovered the positron?

ARutherford
BThomson
CChadwick
DAnderson

Question 15 of 25

The temporary particle in the following is-

AProton
Belectron
CNeutron
Dalpha particles

Question 16 of 25

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 17 of 25

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 18 of 25

Why is nuclear fusion also called thermonuclear reaction?

AFusion converts nuclear energy into heat
BFusion requires extremely high temperature conditions.
CA lot of heat is produced during fusion.
Dnone of these

Question 19 of 25

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 20 of 25

The recently discovered high temperature superconductor is-

Apure rare earth metal
BInorganic polymer
CCeramic Oxide
DMetal Alloys

Question 21 of 25

Radiocarbon dating is used to determine age.

APlanets
Bfossils
Cbabies
Drocks

Question 22 of 25

Who takes three-dimensional pictures?

AHolography
BPhotography
CPhotochromatic
DRadiography

Question 23 of 25

Whose conclusion is the mass energy relation?

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

Question 24 of 25

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 25 of 25

What is the conductivity of a superconductor?

AUnlimited
BLess
CZero
DMore