Free Measurements MCQs with Answers

91. The branch of physics which deals with the properties and interaction of nuclear particles (protons and neutrons) is called:

• A. Molecular Physics
• B. Plasma Physics
• C. Nuclear Physics
• D. Solid state Physics

Explanation: Nuclear physics is the branch of physics that deals with the structure, behavior, and interactions of atomic nuclei. It specifically involves the study of protons and neutrons within the atomic nucleus, as well as the forces that bind these particles together. Nuclear physics encompasses topics such as nuclear reactions, nuclear decay, and nuclear structure.

92. The Physics of Islamic era ranges from:

• A. 3000 BC to 600 AD
• B. 600 AD to 1500 AD
• C. 1500 AD to 1700 AD
• D. 1700 AD to 1750 AD

Explanation: Option D is the correct range for the Physics of the Islamic era. During this period, scholars in the Islamic world made substantial contributions to various scientific disciplines, including physics, astronomy, mathematics, medicine, and optics. The Islamic Golden Age, from the 8th to the 14th century, saw the translation of Greek and Roman texts into Arabic, the preservation of knowledge, and the development of new ideas and theories.

93. The theory of relativity was introduced (in 1905) by:

• A. Planck
• B. Einstein
• C. Maxwell
• D. Rutherford

Explanation: Albert Einstein, a German physicist, introduced the theory of relativity in two parts: the special theory of relativity in 1905 and the general theory of relativity in 1915. The special theory of relativity, encapsulated in the famous equation E=mc², revolutionized our understanding of space, time, and energy. The general theory of relativity extended these ideas to include gravity and described it as the curvature of spacetime caused by mass and energy.

94. The fundamental physics quantities which form the basis for the MKS system are:

• A. Force, weight and time
• B. Mass, length and time
• C. Mass, length and force
• D. Mass, energy and time

Explanation: B is the correct answer. The MKS system is based on three fundamental units: mass (kilogram), length (meter), and time (second). These three quantities form the foundation for measuring other physical quantities in the MKS system.

95. Fundamental units in MKS system are:

• A. Gram, dyne and second
• B. Kilogram, centimetre and second
• C. Kilogram, Newton and second
• D. Kilogram, meter and second

Explanation: D is the correct answer. In the MKS system, the kilogram is the unit of mass, the meter is the unit of length, and the second is the unit of time. These three fundamental units provide the basis for measuring other physical quantities in a coherent and consistent manner.

96. The units which are based on one or more fundamental units are called:

• A. Fundamental units
• B. Derived units
• C. Basic units
• D. None of the above

Explanation: Derived units are formed by combining fundamental units according to the equations of physics or other relationships. For example, the unit of speed is derived by dividing the unit of length by the unit of time (meters per second). Other examples of derived units include the newton (force), pascal (pressure), joule (energy), and watt (power), which are combinations of fundamental units.

97. Which of the following is not a derived unit:

• A. Newton
• B. Meter/sec
• C. Kilogram/meter3
• D. Second

Explanation: The second (s) is a fundamental unit of time in the International System of Units (SI). It is not derived from other units but is considered one of the base or fundamental units. The second is not a derived unit.

98. Which of the following is not a fundamental unit in SI units:

• A. Kilogram
• B. Ampere
• C. Metre3
• D. Kelvin

Explanation: Cubed meters (m³) is not a fundamental unit in SI. While the meter (m) is a fundamental unit for length, the cubic meter is a derived unit, representing the volume of a three-dimensional space.

99. Light year is the unit of:

• A. Time
• B. Distance
• C. Light
• D. Velocity

Explanation: The light year is primarily used to express astronomical distances. It represents the distance that light travels in one year in a vacuum. Since the speed of light is approximately 299,792 kilometers per second, a light year is about 9.461 trillion kilometers.

100. The dimensions of weight are:

• A. ML T-1
• B. ML T-2
• C. LT-2
• D. ML2T

Explanation: The following is the solution: Weight (W) = Mass × Acceleration . . . . . . (1) Since, Acceleration = Velocity × [Time]-1 And, velocity is dimensionally represented as [M0 L1 T-1] ∴ The dimensional formula of acceleration = [M0 L1 T-2] . . . . . (2) The dimensions of mass = [M1 L0 T0] . . . . (3) On substituting equation (2) and (3) in equation (1) we get, Weight = Mass × Acceleration Or, W = [M1 L0 T0] × [M0 L1 T-2] = [M1 L1 T-2].