Physics Basics — Set 2

Correct Answer: C. Albert Einstein

Albert Einstein developed the special and general theories of relativity. These theories revolutionized our understanding of space, time, and gravity. He is also famous for the mass-energy equivalence formula, E=mc².

Correct Answer: C. Wind speed

An anemometer is a common weather station instrument used to measure the speed of wind. Leon Battista Alberti is credited with the earliest description of a mechanical anemometer. It is essential for meteorologists to study weather patterns and wind pressure.

Correct Answer: A. 10^-9

The prefix 'nano' denotes a factor of 10 to the power of negative nine. It is commonly used in nanotechnology to describe scales at the atomic level. For example, one nanometer is one-billionth of a meter.

Correct Answer: D. J.J. Thomson

J.J. Thomson discovered the electron in 1897 through experiments with cathode ray tubes. This discovery proved that atoms were not indivisible but contained smaller particles. He won the Nobel Prize in 1906 for his work on the conduction of electricity in gases.

Correct Answer: D. Pascal

The Pascal is the SI unit of pressure, named after the scientist Blaise Pascal. One Pascal is defined as one Newton of force applied over an area of one square meter. It is a derived unit used in both fluid mechanics and solid mechanics.

Correct Answer: B. James Watt

James Watt significantly improved the steam engine by adding a separate condenser in 1765. This innovation greatly increased the efficiency and power of the engine. His work played a central role in the advancement of the Industrial Revolution.

Correct Answer: A. Frequency

Hertz is the SI unit of frequency, defined as one cycle per second. It is named after Heinrich Rudolf Hertz, who proved the existence of electromagnetic waves. This unit is commonly used to describe the pitch of sound and radio waves.

Correct Answer: C. Lactometer

A lactometer is a specialized hydrometer used to check the purity of milk by measuring its density. It works on the principle of Archimedes regarding buoyancy in liquids. Pure milk has a specific gravity range that the lactometer helps to verify.

Correct Answer: D. Galileo Galilei

Galileo Galilei is often called the father of experimental physics for his use of systematic observation. He championed the use of experiments to validate physical laws rather than relying solely on logic. His work laid the foundations for modern classical mechanics.

Correct Answer: B. 3 x 10^8 m/s

The speed of light in a vacuum is approximately 300,000,000 meters per second. This value is a universal physical constant denoted by the symbol 'c'. It is the maximum speed at which all conventional matter and information can travel.