(c) Some of the energy from the wind used to rotate a wind turbine is wasted An engineer oils the mechanical parts of a wind turbine. Explain how oiling would affect the efficiency of the wind turbine __ (d) In most homes in the UK there are many different electrical devices Explain why people should be encouraged to use energy efficient electrical devices __

## Step1:For question (c), we need to understand the concept of efficiency in the context of a wind turbine. Efficiency refers to the ratio of useful output energy to the total input energy. In the case of a wind turbine, the useful output energy is the electricity generated, while the total input energy is the wind energy used to rotate the turbine.## Step2:The energy wasted in a wind turbine is often due to friction in its mechanical parts. Friction is a force that opposes motion, converting kinetic energy (the energy of motion) into thermal energy (heat). This conversion is a form of energy loss, reducing the efficiency of the turbine.### Formula: Efficiency = ## Step3:Oiling the mechanical parts of a wind turbine reduces friction. This means less kinetic energy is converted into thermal energy, and more is used to generate electricity. Therefore, oiling the turbine increases its efficiency.## Step4:For question (d), we need to understand the concept of energy efficiency in the context of electrical devices. Energy efficient devices are designed to use less energy for the same function, compared to less efficient alternatives.## Step5:Encouraging the use of energy efficient devices has several benefits. It reduces energy consumption, which can lead to lower energy bills for consumers. It also reduces the demand for energy production, which can help conserve natural resources and reduce environmental impact, especially if the energy is sourced from non-renewable resources.