Energy Efficiency

The law of conservation of energy states that when one form of energy is converted into another,

• energy is destroyed in the process
• no energy is destroyed in the process
• energy is created in the process
• some amount of energy cannot be accounted for

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

In energy transformations, "wasted energy" usually takes what form?

• heat
• chemical energy
• light
• sound waves

Tags

NGSS.MS-PS1-4

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

• False

• True

When is energy lost?

• During transformations only

• During transformations and transfers

• During transfers only

• During GPS outages

Tags

NGSS.MS-PS3-5

Energy efficiency of incandescent lightbulbs is

• 50%

• 25%

• 15%

• 5%

With wind-electric turbines, electric energy is turned into rotational energy.

• True

• False

Energy efficiency of wind turbines is about

• 90%

• 75%

• 40%

• 12%

Tags

NGSS.MS-PS3-3

Which type of alternative energy source is shown in this picture?

• Wind
• Solar
• Hydroelectric
• Geothermal

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NGSS.MS-ESS2-4

What is the energy efficiency of hydroelectric dams?

• 90%

• 70%

• 50%

• 29%

Tags

NGSS.MS-PS3-4

The house illustrated here uses panels on the roof to collect a natural resource and convert it into electricity that can be used.
Which alternative energy source does this house use?

• Water
• Wind
• Solar
• Geothermal

Tags

NGSS.HS-PS3-3