Energy Efficiency

A TV uses 200 J of electricity and transforms it into 125 J of sound and light and 75 J of heat. How efficient is it?

• 62.5%

• .625%

• 37.5%

• .375%

Tags

NGSS.HS-PS3-3

Total energy in has to equal

• Total energy out (wasteful + useful)

• Useful energy out

• Useful out - wasteful

The energy output will always be ______________

• less than the energy input

• more than the energy input

What is one way combined heat and power/cogeneration can increase efficiency in energy generation?

• By capturing and utilizing heat

• By using nuclear reactions

• By increasing chemical reactions

• By reducing friction and resistance

Tags

NGSS.HS-PS3-3

NGSS.HS-PS3-4

Which of the following is a way individuals can improve energy efficiency in their homes and automobiles?

• Using incandescent light bulbs

• Keeping windows open during winter

• Using more fossil fuels

• Using energy star appliances

Tags

NGSS.HS-ETS1-3

Which of the following is NOT a way to improve energy efficiency in homes?

• Better insulation and windows

• Tankless water heaters

• Standby settings on electronics

• Running appliances at maximum power

Tags

NGSS.HS-ETS1-3

NGSS.HS-PS3-4

Which factor contributes to energy loss in the generation, transmission, use, and waste of electricity?

• Chemical reactions

• Nuclear reactions

• Friction and resistance

• Gravity and magnetism

What are the factors that contribute to energy loss in the generation, transmission, use, and waste of electricity?

• Chemical reactions

• Friction and resistance

• Nuclear reactions

• Gravity and magnetism

Tags

NGSS.HS-PS2-5

Which factor contributes to the most energy loss in the generation, transmission, use, and waste of electricity?

• Gravity and magnetism

• Chemical reactions

• Friction and resistance

• Nuclear reactions

How can combined heat and power/cogeneration increase efficiency in energy generation?

• By reducing friction and resistance

• By using nuclear reactions

• By increasing chemical reactions

• By capturing and utilizing heat

Tags

NGSS.HS-ESS3-4

NGSS.HS-ETS1-3

NGSS.HS-PS3-4