Grade 9 Natural Science Questions and Answers 2022

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.