Grade 9 Natural Science Questions and Answers for 2022 learners
Grade 9 Natural Science: Multiple-Choice Questions
The primary energy source used in Eskom power plants is….
- A natural gas.
- B uranium.
- C coal.
- D oil.
Correct Answer: C coal
In the diagram below, which number represents the cable that discharges the fault current to the ground?
- A 2
- B 3
- C 4
- D 5
Correct Answer: B
Which one of the following groups of sources of energy is sustainable and has a very small negative impact on the environment?
- A Sun-heated steam, waves in the sea and wind.
- B Coal, nuclear fuel and wind.
- C Earth oil, hydroelectric power and wave power.
- D Solar energy, coal and falling water.
Correct Answer: A
… may cause burns, cancer and gene mutation if the skin is exposed to it due to its radioactive nature.
- A Coal
- B Falling water
- C Steam
- D Nuclear waste
Correct Answer: D
Grade 9 Electric Circuits Questions
Study circuits A, B, C and D and answer questions. All bulbs and cells are identical.
- Which circuit has the highest resistance? (1) Answer: D
- In circuit B, what is the component that is circled? (1) Answer: Battery
- What is the purpose of the component circled? (1) Answer: It is a source of (electrical) energy.
- What is the voltage of each bulb in circuit D? (2) Answer: 1,5 ÷ 3 = 0,5 V
- In which circuit will the bulb/bulbs be the brightest? (1)Answer: B
Mention factors that can influence the resistance of a resistor.
Answers:
- Temperature of the resistor.
- Type of a resistor.
- Thickness of the resistor.
- Length of the resistor.
Study the circuit diagram below and answer the questions that follow. Each cell has a potential difference of 1,5 V. The resistance of bulb S is R and the resistance of bulb T is 4R.
- In which way are bulbs S and T connected? (1) Answer: Parallel
- What is the reading on voltmeter V1? (2) Answer: V1 = 3 x 1,5= 4,5 V
- What is the reading on voltmeter V3? (1) Answer: 4,5
- Which bulb will glow the brightest? S or T? (1) Answer: S
- What will happen to the reading on ammeter A1 if bulb T is switched off? (1) Answer: Reading on A1 will decrease.
- Explain your answer Answer: If T is switched off, there are less resistors in parallel, therefore the total resistance in the circuit will increase, and the total current will decrease.
