Free Physics in Daily Life MCQs with Answers

321. Select the arrangement of electromagnetic radiation which starts with the lowest energy and increases to greatest energy?

• A. radio, visible, infrared, ultraviolet, x-ray, gamma ray
• B. radio, infrared, visible, x-ray, gamma ray, ultraviolet
• C. visible, radio, infrared, ultraviolet, x-ray, gamma ray
• D. radio, infrared, visible, ultraviolet, x-ray, gamma ray

Explanation: Energy increases with frequency and decreases with wavelength: radio, infrared, visible, ultraviolet, X-rays, then gamma rays. Therefore option d gives the correct low-to-high energy order.

322. Which of the following has the largest wavelength?

• A. visible light
• B. x-rays
• C. infrared light
• D. ultraviolet radiation

Explanation: Infrared has a longer wavelength than visible light, ultraviolet radiation, and X-rays. In the electromagnetic spectrum, wavelength decreases as frequency and energy increase.

323. Which of the following has the highest energy?

• A. gamma rays
• B. X-rays
• C. Ultra-violet radiation
• D. radio waves

Explanation: Gamma rays have the highest frequency and therefore the highest energy among the listed electromagnetic radiations. Radio waves have the lowest frequency and energy in this set.

324. All of the following are electromagnetic radiations except__________?

• A. Red light
• B. Sound waves
• C. X-Rays
• D. Photon

Explanation: Red light and X-rays are electromagnetic waves, and photons are the quanta that carry electromagnetic radiation. Sound requires a material medium and is therefore mechanical, not electromagnetic.

325. All of the following statements are incorrect except:

• A. Precision and accuracy should go side by side in a scientific work
• B. Scientific work must be precise, accuracy is not essential
• C. Scientific work must be accurate, precision is not essential
• D. Calculations must be made before any experiment

Explanation: Accuracy means closeness to the true value, while precision means repeatability; reliable scientific work requires both. Precision alone can give closely grouped but incorrect results.

326. The average speed of a moving object during a given interval of time is always:

• A. the magnitude of its average velocity over the interval
• B. the distance covered during the time interval divided by the time interval
• C. one-half its speed at the end of the interval
• D. its acceleration multiplied by the time interval
• E. one-half its acceleration multiplied by the time interval

Explanation: Average speed is defined as the total distance travelled divided by the total time taken. It is not always equal to the magnitude of average velocity because an object may change direction.

327. The SI base unit for mass is_____________?

• A. Gram
• B. Pound
• C. Kilogram
• D. Ounce

Explanation: The kilogram is the SI base unit of mass. Gram, pound and ounce are smaller or non-SI units used for measurement but are not the SI base unit.

328. Which of the following is closest to a yard in length?

• A. 0.01m
• B. 0.1m
• C. 1m
• D. 10m
• E. 100m

Explanation: One yard equals 0.9144 metre, which is closest to 1 metre among the listed choices. The other values differ by factors of ten or more.

329. The SI standard of time is based on_____________?

• A. the daily rotation of the earth
• B. the frequency of light emitted by Kr86
• C. the yearly revolution of the earth about the sun
• D. a precision pendulum clock
• E. none of these

Explanation: The SI second is defined using the frequency of radiation from the caesium-133 atom, specifically 9,192,631,770 cycles. Since no option mentions caesium-133, none of the listed statements is correct.

330. Which is least Conductor of Electricity among the following?

• A. Wood
• B. Copper
• C. Iron
• D. Water

Explanation: Dry wood has very high electrical resistance because it contains few freely moving charge carriers. Copper and iron conduct well, while ordinary water conducts to some extent because of dissolved ions.