Energy Efficiency

No machine in existence has 100% efficiency due to ____________________.

• magic

• friction

• smoke

• input

To save energy, what should you do when you leave a room ?

• USE ELECTRICAL ENERGY

• SHUT OFF THE LIGHTS AND TELEVISION

• TURN ON THE LIGHTS AND TELEVISION

• HANG YOUR CLOTHES OUTSIDE

Another way to save energy is to...

• Conserve it

• Waste it

• Use it

Efficiency is calculated by useful energy output divided by total energy input, expressed as a percentage

• False

• True

Energy efficiency of incandescent lightbulbs is

• 50%

• 25%

• 15%

• 5%

Energy efficiency of wind turbines is about

• 90%

• 75%

• 40%

• 12%

What is the energy efficiency of hydroelectric dams?

• 90%

• 70%

• 50%

• 29%

How much light energy in converted to electrical energy in commercial solar panels?

• 75%

• 60%

• 20%

• 5%

Tags

NGSS.HS-PS3-3

Around how much energy is lost in power lines and transformers?

• 25%

• 10%

• 2%

• 0.1%

Tags

NGSS.HS-PS3-3

An oven uses 400 J of electricity to produce 300 J of heat. How efficient is it?

• 133 %

• 75 %

• 300 %

• .75 %

Tags

NGSS.MS-PS3-3