Ocean Energy Multiple Choice Questions on “Tidal Energy – 1”.
1. What is tidal power?
a) Energy from tides
b) Energy from water
c) Energy from moon
d) Energy from sun
Clarification: Tidal power converts the energy from tides to usable forms. Though tides are water, it is not the same as the energy harnessed from a flowing river. Tides are caused due to moon.
2. Which of the following categories does tidal power fall into?
Clarification: Tidal power comes under the category of hydropower. Hydrothermal is basically energy harnessed from hot water/steam found in geothermal sites. Solar and wind are not related to water.
3. What is/are the cause(s) of tides?
a) Gravitational pull of moon
b) Gravitational pull of moon and sun
c) Gravitational pull of sun and moon and rotation of earth
d) Gravitational pull of sun
Clarification: Tides are caused by the gravitational pull of moon, sun and the rotation of earth. It is the cumulative effect of all the three factors. No single factor individually dominates the other.
4. What is the minimum height of tides required for harnessing tidal energy economically?
a) 1 foot
b) 5 feet
c) 8 feet
d) 10 feet
Clarification: To harness tidal energy economically, the minimum height of the tides should be 10 feet. Most of the plants harness the tidal energy to generate electricity which is either used in remote locations or sent to the grid.
5. In terms of predictability, tidal energy _____ solar and wind.
a) is more predictable than
b) is less predictable than
c) has similar predictability like
d) cannot be predicted unlike
Clarification: In terms of predictability, tidal energy is more predictable than solar and wind. This because of its origins – gravitational forces and earth’s rotation. Intensity of sunlight and wind speeds vary greatly within a day unlike the tides.
6. Tidal barrage is similar to ______
a) wind plant
c) wind turbines
d) coal plant
Clarification: Tidal barrage is similar to a dam. As the name suggests, a barrage (barrier) is constructed across an inlet of an ocean bay to harness the energy.
7. Which of the following best describes the working of a tidal barrage for an incoming tide?
a) Incoming tides → generator → barrage → basin
b) Incoming tides → basin → generator → barrage
c) Incoming tides → barrage → basin → generator
d) Generator → barrage → basin → incoming tides
Clarification: The incoming tides flow through the barrage into the basin. Once the basin is filled, the water is emptied by allowing it to pass through an electric generator thereby generating electricity.
8. Which of the following best describes the working of tidal barrage for outgoing tides?
a) Generator → basin → ocean → outgoing tide
b) Generator → ocean → basin → outgoing tide
c) Ocean → generator → basin → outgoing tide
d) Outgoing tide → generator → basin → ocean
Clarification: The outgoing tides flow through the generator which converts the kinetic energy into electrical energy. The water is then emptied into the ocean via a separate basin.
9. Tidal barrages are a two-way tidal power system.
Clarification: Tidal barrages are a two-way power system. This is because they use both, the incoming and the outgoing tides to generate electricity. The water flow is controlled by sluice gates.
10. Which of the following is a potential problem of a tidal barrage?
a) Impacts on deep sea/ocean marine life
b) Impacts on estuaries of the tidal basin
c) A two-way tidal power system
d) Decrease in turbidity
Clarification: One of the main problems that a tidal barrage can cause is the destruction of estuaries of the tidal basin. Tidal barrages also increase the turbidity of the water near the basin. They don’t affect the deep sea marine life.
11. Which of the following tidal barrages has the largest capacity to generate electricity?
a) La Rance
b) Annapolis Royal
c) The Sihwa Lake Tidal Power Station
d) Russian tidal plants
Clarification: The Sihwa Lake Tidal Power Station in South Korea has the largest capacity to generate electricity. The tidal plant in La Rance, France is the oldest and has the second largest capacity. Next comes the tidal power plant in Annapolis Royal in Nova Scotia.
12. What are the three ways to harness tidal energy?
a) Tidal streams, tidal barrages and wind
b) Tidal barrages, wind and sun
c) Tidal lagoons, river streams and geothermal reservoirs
d) Tidal lagoons, tidal streams and tidal barrages
Clarification: The three different ways to harness tidal energy are tidal streams, tidal barrages and tidal lagoons. Geothermal reservoirs, wind and sun are not tidal resources.
13. The United States has an economical tidal power plant.
Clarification: At the very best, the United States does not have an economical tidal power. China, France, England, Canada and Russia are some of the popular countries known to harness tidal energy.
14. What is a tidal stream?
a) A river streams
b) A fast-flowing body of water due to tides
c) A fast-flowing body of water deposited into ocean
d) A fast-flowing body of water due to winds
Clarification: A tidal stream is a fast-flowing body of water created by tides. It is not the same as a river stream. When compared to a river stream it has a much higher kinetic energy.
15. Tidal generators produce steady and reliable stream of electricity.
Clarification: Tidal generators produce steady and reliable stream of electricity. This is because unlike sun’s intensity and wind speeds which vary over short duration of time, tides are predictable and stable.