Physics Efficiency

What is energy efficiency?

• Energy efficiency is using less energy to provide the same service or achieve the same result.

• Energy efficiency is unrelated to energy consumption.

• Energy efficiency is using more energy to achieve less results.

• Energy efficiency is wasting energy to provide the same service.

Define power consumption.

• Power consumption is the rate at which energy is used or converted by an electrical device.

• Power consumption is the color of an electrical device.

• Power consumption is the speed at which an electrical device operates.

• Power consumption is the amount of water used by an electrical device.

How do you calculate efficiency?

• Efficiency = (Actual Output * Maximum Possible Output) / 100

• Efficiency = (Actual Output - Maximum Possible Output) * 100

• Efficiency = (Actual Output / Total Output) * 100

• Efficiency = (Actual Output / Maximum Possible Output) * 100

Explain the concept of efficiency in simple machines.

• Efficiency in simple machines is the ratio of output work to input work.

• Efficiency in simple machines is the speed at which work is done.

• Efficiency in simple machines is the color of the machine.

• Efficiency in simple machines is the temperature at which the machine operates.

What is the formula for calculating energy efficiency?

• Energy Efficiency = (Output Energy - Input Energy) * 100%

• Energy Efficiency = (Input Energy / Output Energy) * 100%

• Energy Efficiency = (Output Energy / Input Energy) * 100%

• Energy Efficiency = (Output Energy + Input Energy) * 100%

Why is it important to reduce power consumption?

• To accelerate climate change and harm the environment

• To conserve energy resources, reduce electricity bills, lower carbon emissions, and contribute to a more sustainable environment.

• To increase power consumption and boost energy costs

• To support the growth of fossil fuel industries and reduce renewable energy usage

Give an example of a high-efficiency device.

• Halogen light bulb

• Incandescent light bulb

• Fluorescent light bulb

• LED light bulb

How does friction affect the efficiency of a machine?

• Friction increases efficiency by reducing energy loss

• Friction has no impact on the efficiency of a machine

• Friction increases the speed of a machine, thus increasing efficiency

• Friction converts some input energy into heat, reducing efficiency.

Calculate the efficiency of a machine if the input work is 500 J and the output work is 400 J.

• 60%

• 80%

• 75%

• 90%

What are some ways to improve the efficiency of a simple machine?

• Reduce friction, balance the load, and maintain the machine.

• Increase friction, unbalance the load, neglect maintenance