61. What is the main source of energy for hydroelectric power plants?
a. Fossil fuels
b. Solar radiation
c. Wind
d. Water
62. What is the purpose of a dam in a hydroelectric power plant?
a. To regulate the flow of water
b. To store water
c. To increase the pressure of water
d. To decrease the pressure of water
63. Which of the following is a disadvantage of a large hydroelectric power plant?
a. It has a high maintenance cost
b. It requires a large amount of water
c. It has a low efficiency
d. It has a negative impact on the environment
64. Which of the following is a characteristic of a run-of-river hydroelectric power plant?
a. It requires a large amount of water
b. It has a low efficiency
c. It does not require a dam to be built
d. It is only feasible in areas with high tides
65. Which of the following is a disadvantage of a run-of-river hydroelectric power plant?
a. It has a low efficiency
b. It requires a large amount of water
c. It is expensive to build
d. It is not suitable for variable flow rates
