Nuclear Science

Question 1 :

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


A). Thorium
B). Graphite
C). Radium
D). Ordinary water
Answer : Option B

Question 2 :

Which among the following is a positively charged particle emitted by a radioactive element?


A). Beta ray
B). Alpha ray
C). Cathode ray
D). Gamma ray
Answer : Option B

Question 3 :

Atoms are composed of


A). electrons and protons
B). electrons only
C). protons only
D). electrons and nuclei
Answer : Option D

Question 4 :

In an atomic explosion, enormous energy is released which is due to


A). conversion of chemical energy into heat energy
B). conversion of mechanical energy into nuclear energy
C). conversion of mass into energy
D). conversion of neutrons into protons
Answer : Option C

Question 5 :

Isotopes are separated by


A). crystallisation
B). sublimation
C). distillation
D). filtration
Answer : Option C

Question 6 :

The wavelength of X-rays is of the order of


A). 10 micron
B). 1 angstrom
C). 1 cm
D). 1 m
Answer : Option B

Explanation :

1 angstrom = 1.0 x 10-10 meters


Question 7 :

Mesons are found in


A). Laser beam
B). X-rays
C). Gamma rays
D). Cosmic rays
Answer : Option D

Question 8 :

Which radioactive pollutant has recently drawn to public, due to its occurrence in the building material?


A). Thorium
B). Radium
C). Plutonium
D). Radan
Answer : Option A

Question 9 :

Which of the following shows the masses of the three elementary particles in decreasing order?


A). Leptons, Baryons, Mesons
B). Mesons, Baryons, Leptons
C). Baryons, Mesons, Leptons
D). Leptons, Mesons Baryons
Answer : Option C

Question 10 :

What is the wavelength of visible spectrum?


A). 8500 - 9800 angstrom
B). 7800 - 8000 angstrom
C). 3900 - 7600 angstrom
D). 1300 - 3000 angstrom
Answer : Option C

Question 11 :

Which of the following has a least penetrating power?


A). All have same penetrating power
B). Beta Particles
C). Alpha particles
D). Gamma rays
Answer : Option C

Question 12 :

The isotope of uranium capable of sustaining chain reaction is


A). U-235
B). U-245
C). U-239
D). U-238
Answer : Option A

Question 13 :

The age of most ancient geological formations is estimated by


A). Ra - Si method
B). Potassium - argon method
C). C14 method
D). Uranium - lead method
Answer : Option C

Question 14 :

Who suggested that most of the mass of the atom is located in the nucleus?


A). Thompson
B). Bohr
C). Rutherford
D). Einstein
Answer : Option C

Question 15 :

The dark lines in the solar spectrum are due to


A). absorption of corresponding wavelengths by the outer layers of the sun
B). destructive interference between waves of certain definite wavelengths
C). absorption of corresponding wavelengths by the prism used in the photograph
D). absence of corresponding wavelengths from the light emitted by the core of the sun
Answer : Option A

Question 16 :

In an atomic nucleus, neutrons and protons are held together by


A). gravitational forces
B). exchange forces
C). coulombic forces
D). magnetic forces
Answer : Option B

Question 17 :

'No two electrons in an atom can have the same set of four quantum numbers' is


A). Newton's law
B). Bohr's law
C). Aufbau principle
D). Pauli's exclusion principle
Answer : Option D

Question 18 :

According to Avogadro's Hypothesis, the smallest particle of an element or a compound, that can exist independently, is called ____ .


A). a molecule
B). a cation
C). an anion
D). an atom
Answer : Option A

Question 19 :

Atoms of an element differ from those of all other elements in


A). atomic number and electronic configuration
B). number of neutrons and number of valence electrons
C). atomic number and number of valence electrons
D). number of neutrons and electronic configuration
Answer : Option A

Question 20 :

Nuclear fission is caused by the impact of


A). neutron
B). proton
C). deuteron
D). electron
Answer : Option A

Question 21 :

Which of the following rays are more penetrating?


A). Beta rays
B). Alpha rays
C). Gamma rays
D). X-rays
Answer : Option C

Question 22 :

How many colours the sunlight spectrum has?


A). Three
B). Seven
C). Four
D). Five
Answer : Option B