Free Physics in Daily Life MCQs with Answers

281. Which type of motions are present in solid?

• A. translational
• B. rotational
• C. vibrational
• D. all of these

Explanation: Particles in a solid are held in fixed positions and can mainly vibrate about those positions. They do not freely translate through the solid as particles in a liquid or gas do.

282. One Torr is equivalent to how many mm of Mercury?

• A. 1 mm
• B. 10 mm
• C. 100 mm
• D. 0.1 mm

Explanation: A torr is defined as one millimetre of mercury, so 1 torr equals 1 mmHg. It is a unit of pressure, not a length measurement in ordinary use.

283. Sound travels_______ in solid materials then liquid?

• A. Constant
• B. Slowest
• C. Fastest
• D. None of these

Explanation: Sound generally travels fastest through solids because their closely packed particles transmit vibrations efficiently, and slowest through gases. Thus its speed in a solid is greater than in a liquid.

284. All forms of energy that we use are ultimately transformed into__________?

• A. Electrical Energy
• B. Heat Energy
• C. Light Energy
• D. Chemical Energy

Explanation: Energy transformations eventually produce some heat because no practical conversion is perfectly efficient. The other forms listed may be intermediate forms, but heat is the final dissipated form.

285. As the temperature of ice rises, the ice melts and its density?

• A. Decreases
• B. Remain constant
• C. Increases
• D. Increases upto 10C

Explanation: When ice melts into liquid water, its density increases because the open crystal structure collapses. Water then continues becoming denser up to about 4°C, not 10°C.

286. In an oil lamp, the oil rises up in the wick due to?

• A. Capillary action
• B. Atmospheric pressure
• C. Viscosity of oil
• D. Change in temperature

Explanation: Narrow spaces between the fibres of a wick pull oil upward through capillary action, caused by adhesion to the fibres and cohesion within the oil.

287. A man is standing on a weighing machine in a lift which is moving. The weighing machine will slow MINIMUM reading when, the lift is moving?

• A. Upward with uniform speed
• B. Downward with uniform acceleration
• C. In a free fall due to failure of the lift mechanism
• D. None of these

Explanation: In free fall, the lift and the person accelerate downward together at g, so the normal force on the weighing machine becomes zero. Uniform upward motion or ordinary downward acceleration does not reduce the reading as much.

288. A slow-running pendulum clock can be speeded up by_______________?

• A. Increasing the length of the rod
• B. Increasing the weight of the bob
• C. Reducing the length of the rod
• D. Reducing the weight of the bob

Explanation: A pendulum's period increases with the square root of its length, so shortening the rod makes each swing quicker and speeds up the clock. The bob's weight does not determine the period.

289. If there is no capillarity?

• A. It would be impossible to use a kerosene lamp
• B. The blotting paper would fail to function
• C. There would have been no plants on earth
• D. All of above

Explanation: Capillary action draws kerosene up a lamp wick, spreads ink through blotting paper, and helps move water through narrow plant vessels. Without it, all three functions described would be severely affected.

290. Material for rain-proof coats and tents owe their water proof properties to ________?

• A. Surface tension
• B. Viscosity
• C. Specific gravity
• D. Elasticity

Explanation: Surface tension makes water form droplets and resist entering the tiny openings in closely woven or coated fabric, helping raincoats and tents repel water. Viscosity and specific gravity do not provide this waterproofing mechanism.