Physics Mcq Questions | Psc, Wbcs, Upsc, Ssc Exam| rlearn

GENERAL SCIENCE :PHYSICS
Part Number – – – – 2

34. Detergents used for cleaning clothes and utensils contain?

A. Bicarbonates

B. Bismuthates

C. Sulphonates

D. Nitrates

Answer: Option C

Explanation :Detergents used for cleaning clothes and utensils contains sulphonates. They are sodium salt of long chain benzene sulphonic acid or the sodium salt of a long chain alkyl hydrogensulphate.
35. Epoxy resins are used as:

A. Detergents

B. Insecticides

C. Adhesives

D. Moth repellents

Answer: Option C

Explanation :Epoxy resins are used in the manufacture of adhesives, plastics, paints, coatings, primers and sealers, flooring and other products and materials that are used in building and construction applications.
36. Which of the following is commonly called a ‘poly-amide‘?

A. Terylene

B. Nylon

C. Rayon

D. Orlon

Answer: Option B
37. Which type of fire extinguisher is used for petroleum fire?

A. Powder type

B. Liquid type

C. Soda acid type

D. Foam type

Answer: Option A
38. Which is/are the important raw material(s) required in cement industry?

A. Gypsum and Clay

B. Clay

C. Limestone and Clay

D. Limestone

Answer: Option C
39. How many colours the sunlight spectrum has?

A. Three

B. Seven

C. Four

D. Five

Answer: Option B

Explanation :we can observe on the paper that the sunlight is split into a spectrum of colours like a rainbow, every colour in VIBGYOR pattern i.e., violet, indigo, blue, green, yellow, orange and red can be seen. The conclusion drawn here is that sunlight is nothing but a mixture of seven colours.
40. Which of the following rays are the most penetrating?

A. Beta rays

B. Alpha rays

C. Gamma rays

D. X-rays

Answer: Option C

Explanation :Gamma radiation is the most penetrating of the three radiations. It can easily penetrate body tissue.
41. Nuclear fission is caused by the impact of—

A. Neutron

B. Proton

C. Deuteron

D. Electron

Answer: Option A

Explanation :Nuclear fission in fissile fuels is the result of the nuclear excitation energy produced when a fissile nucleus captures a neutron.
42. 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

Explanation :Atoms of an element differ from those of all other elements in number of neutrons and electronic configuration.
43. 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

Explanation :Smallest particle of an element or a compound which is capable of independent existence is called molecule. A molecule is formed when two or more atoms join together chemically.
44. ‘No two electrons in an atom can have the same set of four quantum numbers’ is stated in

A. Newton’s law

B. Bohr’s law

C. Aufbau principle

D. Pauli’s exclusion principle

Answer: Option D

Explanation :’No two electrons in an atom can have the same set of four quantum numbers’ is stated in Pauli’s exclusion principle.
45. 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
46. 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
47. 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

Explanation :The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment.
48. 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

Explanation :Baryons, Mesons, Leptons shows the masses of the three elementary particles in decreasing order.
49. 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.
50. 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

Explanation :Alpha is the least penetrating, while gamma is the most penetrating. Radiation can be harmful, but it can also be useful.
51. 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
52. 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 D

Explanation :The Uranium Lead Method, also known as the U-Pb method, is one of the most ancient and reliable radiometric dating methods. It is used to date rocks and crystals that were formed more than a billion years ago. It has a range of dating samples that are about 1billion to 4.5billion years old. It has a precision rate of 0.1−1 percent.
53. 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 D

Explanation :The Uranium Lead Method, also known as the U-Pb method, is one of the most ancient and reliable radiometric dating methods. It is used to date rocks and crystals that were formed more than a billion years ago. It has a range of dating samples that are about 1billion to 4.5billion years old. It has a precision rate of 0.1−1 percent.
54. Atoms are composed of—

A. Electrons and protons

B. Electrons only

C. Protons only

D. Electrons and Nuclei

Answer: Option D
55. 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
56. Which of the following is used as a moderator in nuclear reactor?

A. Thorium

B. Graphite

C. Radium

D. Ordinary water

Answer: Option D

Explanation :Light water” is the most commonly used moderator (roughly 75% of the world’s reactors) although the term is slightly ambiguous, usually meaning natural fresh water, but could also refer to deuterium-depleted water.
57. Knot is a unit of speed of which of the following?

A. Aeroplane

B. Light waves

C. Ship

D. Sound waves

Answer: Option C
58. Nautical mile is a unit of distance used in—

A. Navigation

B. Road mile

C. Astronomy

D. Measuring the boundaries of a nation

Answer: Option A
59. ‘Bar’ is the unit of

A. Temperature

B. Heat

C. Atmospheric pressure

D. Current

Answer: Option C
60. One Joule is equal to

A. 105 ergs

B. 103 ergs

C. 107 ergs

D. 1011 ergs

Answer: Option C
61. Kilowatt is a unit to measure—

A. Work

B. Power

C. Electricity

D. Current

Answer: Option B

Explanation :The power consumption of small devices is usually measured in Watts, and the power consumption of larger devices is measured in kilowatts (kW), or 1,000 Watts.
62. Electric current is measured by—

A. Commutator

B. Anemometer

C. Ammeter

D. Voltmeter

Answer: Option C

Explanation :An instrument called ammeter measures electric current in a circuit. It is always connected in series in a circuit through which the current is to be measured. Also ammeter has negligible resistance, thus no voltage gets dropped across it.
63. A chronometer measures—

A. Colour contrast

B. Sound waves

C. Time

D. Water waves

Answer: Option C
64. 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

Explanation :Thorium radioactive pollutant has recently drawn attention of public due to its occurrence in the building material.

Thorium is a naturally-occurring, slightly radioactive metal discovered in 1828 by the Swedish chemist Jons Jakob Berzelius, who named it after Thor, the Norse god of thunder. It is found in small amounts in most rocks and soils, where it is about three times more abundant than uranium.

The alpha particles can travel only very short distances through most materials and cannot go through human skin.
65. Mesons are found in

A. Laser beam

B. X-rays

C. Gamma rays

D. Cosmic rays

Answer: Option D

Explanation :Mesons are not produced by radioactive decay, but appear in nature only as short-lived products of very high-energy interactions in matter, between particles made of quarks. In cosmic ray interactions, for example, such particles are ordinary protons and neutrons. Mesons are hadronic subatomic particles composed of one quark and one anti-quark, bound together by the strong interaction. Because mesons are composed of sub-particles, they have a physical size, with a radius roughly one femtometre, which is about 2/3 the size of a proton or neutron. All mesons are unstable, with the longest-lived lasting for only a few hundredths of a microsecond. Charged mesons decay (sometimes through intermediate particles) to form electrons and neutrinos.
66. 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
67. Isotopes are separated by:

A. Crystallisation

B. Sublimation

C. Distillation

D. Filtration

Answer: Option C
68. 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

Explanation :In an atomic explosion, enormous energy is released which is due to the conversion of mass into energy. Since most of the mass of ordinary objects resides in protons and neutrons, converting all the energy of ordinary matter into more useful energy requires that the protons and neutrons be converted to lighter particles, or particles with no rest-mass at all. Based on Einstein’s equation E = mc2, the amount of energy added is relative to the mass gained by the proton multiplied by the speed of light squared. In other words, a lot of energy is converted into a relatively small amount of mass.