Free Physics in Daily Life MCQs with Answers

181. How many grams in an ounce?

• A. 20
• B. 24
• C. 28
• D. 32

Explanation: One ordinary avoirdupois ounce equals 28.3495 grams, conventionally rounded to 28 grams. The other options are too far from the standard conversion.

182. How many ounces in a kg?

• A. 28
• B. 30
• C. 33
• D. 35Physics

Explanation: One kilogram equals 35.274 avoirdupois ounces, which rounds to 35 ounces. Therefore 35 is the nearest listed value.

183. What does Angstrom measure?

• A. Quantity
• B. Speed
• C. Length
• D. None of these

Explanation: An angstrom is a unit of length equal to 10⁻¹⁰ metre, commonly used for atomic radii and wavelengths. It does not measure speed or quantity in general.

184. As you go down into a well, your weight__________?

• A. Slightly increases
• B. Slightly decreases
• C. Remains the same
• D. None of these

Explanation: Weight decreases slightly below Earth's surface because only the mass lying above the object contributes no net inward gravitational pull, reducing the effective gravitational field. This differs from moving upward, where weight also decreases because the distance from Earth's centre increases.

185. Speed of object in one direction is called___?

• A. Velocity
• B. Acceleration
• C. Space
• D. Temperature

Explanation: Velocity is speed together with a specified direction, whereas speed alone has magnitude but no direction. Acceleration means the rate of change of velocity.

186. The Doppler's effect is applicable for_________?

• A. light waves only
• B. sound waves only
• C. Both Light waves and sound ways
• D. None of these

Explanation: The Doppler effect occurs when relative motion changes the observed frequency of a wave. It applies to sound and electromagnetic waves such as light, although light requires a relativistic treatment at very high speeds.

187. SONAR is based on the principle of___________?

• A. Echo
• B. reverberation
• C. resonance
• D. None of these

Explanation: SONAR sends ultrasonic waves into water and detects the returning reflection, or echo, to determine distance or locate objects. Reverberation is the persistence of sound caused by repeated reflections, not the basic operating principle of SONAR.

188. Nuclear sizes are expressed in a unit named ?

• A. Tesla
• B. Force
• C. Fermi
• D. Newton

Explanation: Nuclear dimensions are commonly expressed in femtometres, historically called fermis, where 1 fermi equals 10⁻¹⁵ metre. Tesla measures magnetic field, while newton measures force.

189. Which types of waves are used in a night vision apparatus ?

• A. Radio Waves
• B. Micro Waves
• C. Infrared Waves
• D. Magnetic waves

Explanation: Night vision devices detect infrared radiation emitted or reflected by objects, often converting it into a visible image. Radio and microwave waves are not the usual radiation used for ordinary night vision.

190. SI unit of light is _________ ?

• A. watt
• B. Pascal
• C. Candela
• D. Joule

Explanation: Candela is the SI base unit of luminous intensity, the measurement usually intended by the phrase “intensity of light.” Lumen measures luminous flux, while watt measures power.