What do wind turbines, hydroelectric dams, and ethanol plants have in common?

A. All produce electrical current with pollution
B. All use generators to produce electrical current
C. All convert gravitational potential energy to electrical current
D. All convert thermal energy to electrical current

Question

What do wind turbines, hydroelectric dams, and ethanol plants have in common?

A. All produce electrical current with pollution
B. All use generators to produce electrical current
C. All convert gravitational potential energy to electrical current 
D. All convert thermal energy to electrical current

anonymous · Answer

Korosh23 can you help me??

korosh23 · Answer

B for all require generators to convert one source of power, wind, water and fuel to produce an electric current. 

 If you take the manufacturing process into account then the answer A is invalid, for pollution is created throughout this process, think of the manufacturing steps for example in a dam, the shear volume of cement used to create the dam, the steel reinforcing, the machinery used to build it and the exhaust fumes from these etc.

anonymous · Answer

Thx korosh, I was thinking that it was B but I wasn't sure but thank you clearing it up for me

wmj259 · Answer

Answer is B, because all power plants have to convert the steam/ kinetic energy into electrical energy and generators are how it is done.