Natural Science Grade 9 Term 3 test papers pdf
Natural Science Grade 9 Term 3 test papers pdf
Questions and Answers from Grade 9 Natural Science Term 3 Test Papers
What is the primary energy source used in Eskom power plants?
The primary energy source used in Eskom power plants is coal.
- Explanation: Eskom, South Africa’s main electricity supplier, predominantly relies on coal to generate electricity. Coal is abundant in South Africa, making it a cost-effective option for large-scale power production. However, coal is also a significant contributor to greenhouse gas emissions and environmental pollution, which has led to increased interest in renewable energy sources.
Which one of the following groups of energy sources is sustainable and has a minimal negative impact on the environment?
The correct answer is Sun-heated steam, waves in the sea, and wind.
- Explanation: This group includes renewable energy sources like solar energy, wind power, and wave energy, all of which have low environmental impact compared to fossil fuels. They are sustainable because they can be naturally replenished, and they produce minimal pollution, making them crucial in combating climate change and promoting environmental sustainability.
What may cause burns, cancer, and gene mutation if the skin is exposed to it due to its radioactive nature?
The correct answer is nuclear waste.
- Explanation: Nuclear waste is hazardous because it contains radioactive materials that can remain dangerous for thousands of years. Exposure to radioactive waste can cause severe health problems, including burns, cancer, and genetic mutations. Proper disposal and management of nuclear waste are critical to prevent these harmful effects on humans and the environment.
What is a facility that generates electricity through different processes?
The correct answer is Power Station.
- Explanation: A power station is an industrial facility used to generate electricity. Depending on the type of power station, it may use coal, nuclear, hydroelectric, or renewable energy sources to produce electricity, which is then distributed to homes and businesses.
What instrument is used to measure potential difference?
The correct answer is Voltmeter.
- Explanation: A voltmeter is an instrument designed to measure the potential difference (voltage) between two points in an electrical circuit. This measurement is essential in ensuring the correct functioning of electrical systems and devices.
What equipment is used to step up or step down the voltage?
The correct answer is Transformer.
- Explanation: A transformer is an electrical device used to increase (step up) or decrease (step down) the voltage in an electrical circuit. Transformers are critical in the distribution of electricity from power stations to consumers, ensuring that the voltage is at a safe and usable level.
What is the rate of electrical energy supply?
The correct answer is Electrical power.
- Explanation: Electrical power refers to the rate at which electrical energy is supplied or consumed. It is measured in watts (W) and is a key concept in understanding how much energy an electrical device uses or how much is being supplied by a source.
What safety device trips due to a current overload in a circuit?
The correct answer is Circuit breaker.
- Explanation: A circuit breaker is a crucial safety device in electrical circuits. It automatically cuts off the electrical flow when it detects a current overload, preventing potential damage to the system or even fires. Circuit breakers are essential for maintaining electrical safety in homes and industrial settings.
What is an instrument used to measure current?
The correct answer is Ammeter.
- Explanation: An ammeter is an instrument used to measure the flow of electric current in a circuit. It measures the current in amperes (A) and is essential for monitoring and controlling electrical circuits to ensure they operate correctly.