62- The age of most ancient geological formations is estimated by:
A. RA-S method
B. Potassium-argon
C. ¹⁴C method
D. Uranium-lead method
View Answer
Answer : B. Potassium-argon
Description
63- Which of the following is used as a moderator in nuclear reactor?
A. Graphite
B. Thorium
C. Radium
D. Ordinary water
View Answer
Answer : A. Graphite
Description
64- Isotopes are separated by:
A. Filtration
B. Sublimation
C. Distillation
D. Crystallization
View Answer
Answer : C. Distillation
Description
65- Who suggested that most of the mass of the atom is located in the nucleus?
A. Bohr
B. Thompson
C. Rutherford
D. None of these
View Answer
Answer : C. Rutherford
Description
66- Mesons are found in:
A. Y-rays
B. Laser beam
C. X-rays
D. Cosmic rays
View Answer
Answer : D. Cosmic rays
Description
67- An atom of an element with mass number 23 and atomic number 11 will have:
A. 11 neutrons, 12 protons and 11 electrons
B. 11 protons, 12 neutrons and 11 electrons
C. 11 neutrons, 12 protons and 12 electrons
D. 23 protons and 11 electrons
View Answer
Answer : B. 11 protons, 12 neutrons and 11 electrons
Description
68- The location and energy of an electron in an atom can be specified by:
A. Atomic mass
B. Atomic number
C. Quantum numbers
D. None of these
View Answer
Answer : C. Quantum numbers
Description
69- Old-written material, which cannot be read easily, can be read by:
A. Cosmic rays
B. Ultraviolet rays
C. Infra red rays
D. None of these
View Answer
Answer : B. Ultraviolet rays
Description
70- In an atomic nucleus, neutrons and protons are held together by:
A. Exchange forces
B. Columbic forces
C. Magnetic forces
D. Gravitational forces
View Answer
Answer : A. Exchange forces
Description
71- Which of the following elements is non-radioactive?
A. Uranium
B. Thorium
C. Plutonium
D. Zirconium
View Answer
Answer : D. Zirconium
Description
72- A moderator is used in nuclear reactors in order to:
A. Accelerate the neutrons
B. Slow down the speed of neutrons
C. Decrease the number of neutrons
D. Increase the number of neutrons
View Answer
Answer : B. Slow down the speed of neutrons
Description
73- According to Dalton's atomic theory, the smallest particle which can exist independently is:
A. An atom
B. A molecule
C. Action
D. An anion
View Answer
Answer : A. An atom
Description
74- Which of the following are examples of electromagnetic waves?
1. X-rays 2. Ultrasonic 3. Beta rays 4. Alpha rays
A. 1 only
B. 2 only
C. 4 only
D. 2, 3 and 4
View Answer
Answer : A. 1 only
Description
75- The dark lines in the solar spectrum are due to:
A. Absorption of corresponding wavelengths by the prism used in the spectrograph
B. Destructive interference between waves of certain definite wavelengths
C. Absorption of corresponding wavelengths by the outer layers of the Sun
D. Absence of corresponding wavelengths from the light emitted by the core of the Sun
View Answer
Answer : C. Absorption of corresponding wavelengths by the outer layers of the Sun
Description
76- The correct sequence of various regions in absorption spectrum is:
A. Visible, ultraviolet, microwave, infrared
B. Infrared, gamma ray, ultraviolet
C. Ultraviolet, visible, infrared, microwave
D. Microwave, visible, infrared, X-rays
View Answer
Answer : C. Ultraviolet, visible, infrared, microwave
Description
77- The wavelength of X-ray is of the order of:
A. 1 cm
B. 1 m
C. 10 m
D. 1 Angstrom
View Answer
Answer : D. 1 Angstrom
Description
78- The recent atomic weight scale is based on:
A. ²H
B. ¹H
C. ¹²C
D. ¹⁶O
View Answer
Answer : C. ¹²C
Description
79- No two electrons in an atom can have the same set of four quantum numbers is:
A. Bohr’s law
B. Aufbau principle
C. Newton’s law
D. Pauli’s exclusion principle
View Answer
Answer : D. Pauli's exclusion principle
Description
80- Consider the following statements:
1. Gamma rays are not constituents of nuclei but they are emitted when a nucleus in an excited state returns to its normal state.
2. The neutron to proton ratio for stable nuclei is always less than one.
3. Beta rays consist of ordinary electrons which are of nuclear origin but do not revolve in orbits.
4. Both X-rays and gamma rays are electromagnetic radiations.
