Free Physics in Daily Life MCQs with Answers

201. What is the wavelength of visible spectrum:

• A. 1300-3000A
• B. 3900-7600A
• C. 7800-8000A
• D. None of these

Explanation: Visible light has wavelengths of approximately 3900 to 7600 angstroms, equivalent to about 390 to 760 nanometres. Ultraviolet lies below this range and infrared lies above it.

202. Sound of frequency below 20 Hz is:___________?

• A. Audiosonic
• B. Infrasonic
• C. Ultrasonic
• D. Supersonic

Explanation: Infrasonic sound has a frequency below 20 hertz, below the lower limit of normal human hearing. Ultrasonic sound is above about 20,000 hertz.

203. Mach number is used in connection with the speed of___________?

• A. Ship
• B. Light
• C. Sound
• D. aircraft

Explanation: Mach number compares an object's speed with the local speed of sound and is commonly used to describe aircraft speed. Mach 1 means travelling at the speed of sound.

204. 1 Coulomb = ___________ e.

• A. 6×10-19
• B. 6.25×1018
• C. 1.6×1019
• D. 6.25×10-18

Explanation: One coulomb equals the charge of approximately 6.25 × 10^18 electrons, since the charge of one electron is about 1.6 × 10^-19 coulomb. The negative sign belongs to each electron’s charge, not to the number of electrons.

205. Fathom is the unit of measurement for__________?

• A. Sound
• B. Depth
• C. Energy
• D. Time

Explanation: A fathom is a traditional unit of depth, especially for measuring water depth, equal to six feet or about 1.83 metres. It is not a unit of sound, energy, or time.

206. The study of forces acting upon bodies in motion in the air is called__________?

• A. Aeronautics
• B. Aerophysics
• C. Aerodynamics
• D. Aerofraction

Explanation: Aerodynamics examines how air affects moving bodies, including lift, drag and air resistance. Aeronautics is the broader field concerned with aircraft and flight.

207. Which of the following cutting conditions greatly affects the tool wear?

• A. Cutting speed
• B. Feed
• C. Depth of cut
• D. None of the above

Explanation: Cutting speed strongly affects tool wear because higher speed raises the cutting temperature and accelerates wear mechanisms. Feed and depth of cut also matter, but cutting speed is usually the dominant condition.

208. Very High Frequency (VHF) have __________ wavelengths?

• A. shorter
• B. shortest
• C. longer
• D. longest

Explanation: For the same wave speed, wavelength decreases as frequency increases, according to v = fλ. VHF therefore has shorter wavelengths than lower-frequency radio bands, though not necessarily the shortest of all waves.

209. What do you mean by Phonetics?

• A. Study of speech sounds
• B. Study of language and rules
• C. Study of insects
• D. Study of meaning and syntax

Explanation: Phonetics is the study of speech sounds, including how they are produced, transmitted and heard. The study of meaning and syntax belongs mainly to semantics and grammar, not phonetics.

210. 1 yard =___________?

• A. 3 feet
• B. 6 feet
• C. 2.4 feet
• D. 12 feet

Explanation: A yard is a traditional length unit equal to three feet or 36 inches. Therefore, 1 yard = 3 feet.