Free Measurements MCQs with Answers

141. Which one of the following is a fundamental quantity?

• A. Area
• B. Candela
• C. Acceleration
• D. Velocity

Explanation: The candela is a fundamental quantity. It is the SI unit of luminous intensity, which measures the brightness of light. Luminous intensity is considered a fundamental quantity in the SI system.

142. The special theory of relativity was published 1905 by:

• A. Lorentz
• B. Schrodinger
• C. Einstein
• D. Max Plank

Explanation: Albert Einstein is the correct answer. He introduced the theory of special relativity in 1905, which revolutionized our understanding of space, time, and gravity. In 1915, he extended his work to the theory of general relativity, providing a more comprehensive understanding of gravity as the curvature of spacetime.

143. Which one of the following is not a fundamental unit?

• A. Erg
• B. Meter
• C. Kelvin
• D. Ampere

Explanation: The erg is not a fundamental unit; it is a derived unit. The erg is a unit of energy and work in the centimeter-gram-second (CGS) system. In the International System of Units (SI), the fundamental unit of energy is the joule (J).

144. The SI system of units comprises of:

• A. Three basic units
• B. Five basic units
• C. Six basic unit
• D. Seven basic units

Explanation: This is the correct answer. The SI system consists of seven base units, which are: Meter (m) - unit of length Kilogram (kg) - unit of mass Second (s) - unit of time Ampere (A) - unit of electric current Kelvin (K) - unit of temperature Mole (mol) - unit of amount of substance Candela (cd) - unit of luminous intensity These seven base units are used to define and derive all other units in the SI system. The combination of these units allows for the consistent measurement of a wide range of physical quantities.

145. Pinhole camera was invented by:

• A. Al-Beruni
• B. Yaqoob Al-Kindi
• C. Ibn-Al-Haitham
• D. Al-Khwarizmi

Explanation: The pinhole camera, also known as the camera obscura, is an optical device that uses a small hole or aperture to project an inverted image of the external scene onto a flat surface. The invention of the pinhole camera is attributed to various historical figures, but Ibn al-Haytham (also known as Alhazen) is often credited with significant advancements in understanding the camera obscura.

146. Physics is one of the branches of:

• A. Life sciences
• B. Physical science
• C. Biological sciences
• D. Social sciences

Explanation: B is the correct answer. Physics is one of the branches of physical science. Physical science is a broad category that includes physics, chemistry, astronomy, and earth science. These disciplines collectively investigate the non-living, physical aspects of the universe.

147. The famous Mathematician and founder of Algebra was:

• A. Al Kindi
• B. Al Khwarizmi
• C. Al Beruni
• D. Naseruddin Tusi

Explanation: Al-Khwarizmi is the correct answer. He was a Persian mathematician, astronomer, and geographer who lived during the 9th century. Al-Khwarizmi played a pivotal role in the development of algebra. His work "Kitab al-Mukhtasar fi Hisab al-Jabr wal-Muqabala" (The Compendious Book on Calculation by Completion and Balancing) is a foundational text that introduced systematic methods for solving linear and quadratic equations, laying the groundwork for algebra as a distinct branch of mathematics.

148. Zero is significant only if it:

• A. Lies to the left of the significant digit
• B. Is between two digits
• C. Is after the decimal point
• D. Is before the decimal point

Explanation: Zeros between nonzero digits are considered significant. For example, in the number 205, the zero is considered a significant figure.

149. A second is defined as the duration of vibration of:

• A. Carbon atom
• B. Caesium atom
• C. Radium atom
• D. Nitrogen atom

Explanation: B is the correct answer. The current definition of a second is based on the vibrations associated with the caesium-133 atom. The International System of Units (SI) defines a second as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium-133 atom.

150. The most basic branch "Mechanics" of physics deals with the:

• A. Gravitational, electromagnetic and nuclear fields
• B. Acoustics
• C. Motion of particles under forces
• D. Optics

Explanation: Option C correctly aligns with the fundamental concept of mechanics, as it involves studying how objects move when subjected to various forces.