SET 01
🎯 Objectives: NECTA Physics Form Four CONCEPTUAL Questions and Answers
NECTA Form Four Conceptual Physics Questions and Answers
Total: 50 Questions and Answers | Competence-Based | NECTA Format
Conceptual Physics Questions
1. Explain why a passenger standing in a moving bus falls forward when the bus suddenly stops.
Due to inertia, the passenger's body tends to remain in motion while the bus stops, causing them to fall forward.
2. Why is the boiling point of water lower at higher altitudes?
At higher altitudes, atmospheric pressure is lower, so water boils at a lower temperature.
3. What is the purpose of using convex mirrors in vehicles?
Convex mirrors provide a wider field of view, allowing drivers to see more of the road behind them.
4. Why does a balloon expand when taken to higher altitudes?
As atmospheric pressure decreases with altitude, the internal pressure causes the balloon to expand.
5. Explain why metals feel colder than wood at room temperature.
Metals are better conductors of heat, so they draw heat from the hand more quickly than wood.
6. Why does sound travel faster in solids than in gases?
Particles in solids are closely packed, allowing vibrations (sound) to transfer faster.
7. How does a fuse protect an electrical appliance?
It melts when current exceeds the safe level, breaking the circuit and preventing damage.
8. Why is a black object a good absorber of heat?
Black surfaces absorb all wavelengths of light and convert them into heat.
9. Why do we see lightning before hearing thunder?
Light travels much faster than sound, so it reaches the eyes before the sound reaches the ears.
10. What is the advantage of using a step-up transformer in power transmission?
It increases voltage and reduces current, minimizing power loss due to resistance in wires.
11. Why do raindrops fall to the Earth?
Due to gravitational attraction of the Earth acting on their mass.
12. Why does a body float in water?
If the buoyant force acting on it equals or exceeds its weight.
13. Why does heating increase pressure in a sealed container of gas?
Particles move faster and collide more often with the walls, increasing pressure.
14. What is the function of oil in a transformer?
It acts as a coolant and an insulator.
15. Why does ice float on water?
Ice is less dense than liquid water due to the molecular structure of solid water.
16. Explain why sharp knives cut better than blunt ones.
Sharper edges apply more pressure over a smaller area, making cutting easier.
17. Why do planets revolve around the sun?
Due to the gravitational pull of the sun and their tangential velocity.
18. What causes echoes?
Echoes are caused by the reflection of sound waves from a surface back to the listener.
19. How does pressure affect the boiling point of a liquid?
Increasing pressure raises the boiling point; decreasing pressure lowers it.
20. Why do electric irons have thermostats?
To regulate the temperature automatically and prevent overheating.
21. Why does a stretched rubber band return to its original shape?
Elastic materials return to their original shape due to restoring forces.
22. Why do we wear white clothes in hot weather?
White reflects most of the sunlight and keeps the body cooler.
23. Why are steel bridges built with expansion gaps?
To allow for expansion and contraction due to temperature changes.
24. Why is it easier to lift a heavy object in water than in air?
Water provides a buoyant force that reduces the effective weight of the object.
25. Why does a compass needle always point North?
Due to alignment with Earth’s magnetic field lines.
26. Why do electric charges repel or attract each other?
Due to electrostatic forces between like or unlike charges.
27. Why do transformers work only with AC?
Transformers rely on changing magnetic fields, which only AC provides.
28. Why does a bar magnet come to rest in a North-South direction?
Due to alignment with Earth’s magnetic field.
29. Why is current conserved at a junction?
Due to the law of conservation of charge.
30. Why do electric bulbs glow?
Because the filament heats up due to resistance and emits light.
31. Why are metals good conductors of electricity?
They have free electrons that move and carry charge easily.
32. Why does a rocket move upward?
Due to Newton’s third law: the downward thrust of gases pushes the rocket upward.
33. Why is a lunar eclipse not seen every full moon?
Because the Moon's orbit is tilted relative to Earth's orbit.
34. Why does rubbing a balloon on hair cause it to stick to a wall?
Friction causes static electricity which attracts the balloon to the wall.
35. Why does a bicycle stop when brakes are applied?
Due to friction between the brake pads and the wheel.
36. Why are radiators painted black?
Black surfaces are better emitters of heat.
37. Why is mercury used in thermometers?
It expands uniformly and is visible in glass tubes.
38. Why does a moving object eventually stop?
Due to opposing forces such as friction or air resistance.
39. Why does a satellite remain in orbit?
Because its centripetal force balances gravitational pull.
40. Why do objects appear bent in water?
Due to refraction of light as it changes medium from water to air.
41. Why are brakes on bicycles made of rubber?
Rubber provides high friction which helps in stopping motion.
42. Why do air bubbles in water rise to the surface?
Because air is less dense than water, so buoyant force acts upward.
43. Why do hot air balloons rise?
Hot air is less dense than cool air, creating lift.
44. Why does a body accelerate down a slope?
Due to the component of gravitational force acting along the slope.
45. Why are circuit breakers better than fuses?
They can be reset and respond faster to overcurrent.
46. Why is water not a good conductor of electricity in pure form?
Because it lacks free ions or impurities to carry current.
47. Why do electric kettles boil water faster?
They transfer heat directly to the water through immersion elements.
48. Why do heavier objects not fall faster than lighter ones in a vacuum?
Because acceleration due to gravity is the same for all objects.
49. Why are metals used for cooking utensils?
They conduct heat efficiently.
50. Why does the pressure increase with depth in liquids?
Because of the weight of the liquid above the point of measurement.
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