O-Level Combined Science — Physics 2 — Questions and Answers
Question 1: Which of the following is a good conductor of electricity?
- Rubber
- Plastic
- Copper (Correct answer)
- Glass
Correct answer: Copper
Copper is an excellent conductor of electricity due to its free electrons that can move easily.
Question 2: What happens to the resistance of a wire if its length is doubled?
- Halved
- Remains the same
- Quadrupled
- Doubled (Correct answer)
Correct answer: Doubled
Resistance is directly proportional to length (R = ρL/A). Doubling the length doubles the resistance.
Question 3: A wave has frequency 50 Hz and wavelength 4 m. What is its speed?
- 12.5 m/s
- 200 m/s (Correct answer)
- 54 m/s
- 46 m/s
Correct answer: 200 m/s
Wave speed = frequency × wavelength = 50 × 4 = 200 m/s.
Question 4: What is the principle of conservation of energy?
- Energy can be created but not destroyed
- Energy can be destroyed but not created
- Energy cannot be created or destroyed, only converted (Correct answer)
- Energy always decreases over time
Correct answer: Energy cannot be created or destroyed, only converted
The principle of conservation of energy states that energy cannot be created or destroyed, only converted from one form to another.
Question 5: Which colour of visible light has the highest frequency?
- Red
- Orange
- Yellow
- Violet (Correct answer)
Correct answer: Violet
In the visible spectrum, violet light has the highest frequency (and shortest wavelength), while red has the lowest frequency.
Question 6: What does an ammeter measure?
- Voltage
- Resistance
- Current (Correct answer)
- Power
Correct answer: Current
An ammeter measures electric current in amperes (A) and is connected in series in a circuit.
O-Level Combined Science — Physics 2
Which of the following is a good conductor of electricity?