Energy sources : แบบฝึกหัด

Which of the following energy sources relies on the kinetic energy of moving air to generate electricity?

An electric motor is supplied with \(400\text{ J}\) of electrical energy. During its operation, it produces \(320\text{ J}\) of useful kinetic energy to lift a weight. What is the efficiency of this motor?

Consider the use of solar energy versus natural gas for electricity generation. Which statement accurately describes a key benefit of one and a key drawback of the other?

Biomass energy is an alternative energy source. Which of the following is a common source of biomass?

Which of the following actions best demonstrates a commitment to saving energy in daily life?

State one reason why coal and oil are classified as non-renewable energy sources according to the curriculum.

A machine is designed with an energy conversion efficiency of \(75\%\). If the total electrical energy input to the machine is \(800\text{ J}\), calculate the amount of useful energy output produced.

Explain why biomass energy is theoretically described as carbon neutral and identify one factor during its production lifecycle that could cause it to contribute to a net increase in greenhouse gases.

Energy sources are classified into renewable and non-renewable categories.
(a)<\/b> Define the term 'renewable energy source'.
(b)<\/b> Name one example of a renewable energy source and one example of a non-renewable energy source.
(c)<\/b> Why is coal considered a non-renewable energy source even though it is formed from natural plant matter?<\/p>

Solar energy is a popular alternative energy source in many countries.
(a)<\/b> Describe the primary energy conversion that takes place in a solar cell.
(b)<\/b> List one reason why solar energy is considered 'clean' compared to burning coal.
(c)<\/b> Explain one limitation of relying entirely on solar energy for a city's electricity supply.<\/p>