Unit Review

Question 1 of 15

Water in a reservoir behind a dam has more ______than water at a lower level.

A. Kinetic energy

B. Electrical potential

C. Gravitational potential energy

D. Mechanical energy

Question 2 of 15

Once built, a hydropower plant typically has lower maintenance and operational costs than other types of power plants. Why, then, is only a small percentage of U.S. electricity generated by hydropower?

A. A ready supply of flowing water is not always available.

B. There is a high risk when damming up large bodies of water.

C. Recreational use of reservoirs limits the amount of water available to generate electricity.

D. Downstream demand for irrigation limits the use of hydropower.

Question 3 of 15

What energy transformations typically occur in a hydropower plant?

A. Potential energy --> kinetic energy --> rotational energy --> electrical

B. Potential energy --> kinetic energy --> mechanical energy --> electrical

C. Kinetic energy --> potential energy --> momentum --> electrical energy

D. Kinetic energy --> potential energy --> linear energy --> electrical energy

Question 4 of 15

In what physical phase does most of the earth's fresh water exist?

A. Gaseous

B. Plasma

C. Liquid

D. Solid

Question 5 of 15

Why does evaporation place more water vapor into the atmosphere than transpiration?

A. Because evaporation is a simpler process and requires less energy

B. Because oceans cover more of the Earth's surface than land

C. Because not all plants transpire water vapor

D. All of the above

Question 6 of 15

About ____ of the Earth's surface is covered by water.

A. 97 percent

B. 76 percent

C. 3 percent

D. 24 percent

Question 7 of 15

Tides, i.e., the regular rise and fall of the ocean level, are caused by:

A. The uneven weight distribution of sea water

B. The Earth's rotation

C. The Earth's orbit

D. Gravity

Question 8 of 15

The hydrologic cycle is powered by ______.

A. The sun

B. Water

C. Evaporation

D. Condensation

Question 9 of 15

During condensation, ________.

A. Vapor turns to liquid

B. Vapor turns to solid

C. Liquid turns to vapor

D. Liquid turns to solid

Question 10 of 15

Why is electricity produced by hydropower expected to decrease?

A. Hydroelectricity pollutes more than other renewable energy resources

B. Hydroelectricity is not easily controlled and is unreliable

C. Hydroelectricity has some environmental disadvantages

D. All of the above

Question 11 of 15

Hydroelectric power uses ___________ to turn turbines.

A. Air

B. Water

C. Steam

D. Gas

Question 12 of 15

Which type of hydropower facility produces and consumes electricity?

A. Run-of-river

B. Diversion dam

C. Pumped storage dam

D. Tidal dam

Question 13 of 15

According to this chart, how much total hydroelectric power was consumed in the U.S. in 2005?

A. 2.5 quads

B. 3.5 quads

C. 4.5 quads

D. 6 quads

Question 14 of 15

A 15-meter tidal turbine can generate as much energy as a 60-meter diameter wind turbine because ___.

A. Tidal power provides uninterrupted electric generation, but wind speeds vary

B. Seawater is much denser than air

C. Tidal turbines are submerged in water

D. Salt water increases the buoyancy of the turbine

Question 15 of 15

Why are the most favorable wave-energy sites generally western coastlines facing an open ocean?

A. Because the unimpeded distance the wind travels over an ocean's surface is greatest on western coastlines

B. Because the jet stream moves from west to east

C. Because thermohaline circulation is greater on western coastlines

D. Because surface ocean currents move clockwise in the northern hemisphere and counterclockwise in the southern hemisphere