Free Physics in Daily Life MCQs with Answers

21. The cracking sound heard when dry hair is combed with a hard rubber comb is due to_________?

• A. The hair barging against the charged comb
• B. Small electric sparks
• C. The rubbing of the comb with the hair
• D. None of the above

Explanation: Rubbing the rubber comb against dry hair transfers electric charges to the comb and hair. The sudden discharge of these charges produces tiny sparks and the cracking sound.

22. Scalding with steam is more severe than scalding by boiling water because_______?

• A. Steam can penetrate the skin
• B. Steam is at a higher temperature
• C. Steam contains more energy than boiling water
• D. Steam is at a higher pressure

Explanation: Steam transfers extra energy when it condenses into water on the skin, releasing its latent heat of vaporization. Therefore steam at the same nominal boiling temperature can cause a more severe burn than boiling water.

23. Water is a highly effective coolant for a car engine because _________?

• A. Water is good conductor of heat
• B. Water has very high specific heat capacity
• C. Water boils at a comparatively high temperature
• D. Evaporation of water produces lot of cooling

Explanation: Water has a high specific heat capacity, so it absorbs a large amount of engine heat while its own temperature rises relatively slowly. This makes it effective for circulating heat away from the engine.

24. A train goes past a railway station at a high speed. A young boy standing on the edge of the platform is likely to __________?

• A. Remain unaffected
• B. Fall away from the train
• C. Fall towards the train
• D. Fall away from or towards the train depending upon the speed

Explanation: Fast-moving air beside the train lowers the pressure there, while the air on the other side exerts relatively greater pressure. This unbalanced pressure can push the boy towards the train.

25. Which one of the following sets of color combinations is added in color vision in TV'?

• A. Red, green and blue
• B. Orange, back and violet
• C. White. red and yellow
• D. Yellow, green and blue

Explanation: Television screens use additive colour mixing, in which red, green and blue light combine in different intensities to produce other colours. This differs from pigment mixing used with paints.

26. A Fahrenheit thermometer indicates a temperature of ' 14°F. its corresponding reading on the Celsius scale will be _________?

• A. - 2O°C
• B. - 10°C
• C. + 10°C
• D. + 20°C

Explanation: Use Celsius = (Fahrenheit minus 32) × 5/9. Thus (14 - 32) × 5/9 = -10°C.

27. Lead ball falls through water more slowly than through air because __________?

• A. The value of 'g' is less in water
• B. Density of air is less than that of water
• C. Of the viscous force in water
• D. Of The surface tension of water

Explanation: Water exerts greater viscous resistance on the falling ball than air does, opposing its motion more strongly. The value of gravitational acceleration is essentially the same in air and water.

28. The rear view mirror of a motor vehicle is ________?

• A. Concave
• B. Plane
• C. Convex
• D. Biconcave

Explanation: A convex mirror gives a wider field of view, allowing the driver to see more of the road behind. It forms upright, diminished images, unlike a concave mirror in ordinary rear-view use.

29. Bats can also fly in dark because they are capable of taking the help of _________?

• A. Ultraviolet Waves
• B. Ultrasonic Waves
• C. Electromagnetic Waves
• D. Special Retina

Explanation: Bats emit ultrasonic sounds and use the returning echoes to locate objects and prey, a process called echolocation. Ultrasonic waves have frequencies above the human hearing range.

30. T.V. transmission cannot cover a very large area because

• A. the strength of T.V. waves is very limited
• B. picture cannot be transmitted clearly after a specific distance
• C. the shape of the earth is spherical
• D. the air is not a good conductor of light and sound/waves

Explanation: TV signals generally travel by line of sight, so the Earth's curved surface blocks them beyond the horizon. This is why transmitters, relay stations and satellites are used to extend coverage.