Tag: structure of earth

Questions Related to structure of earth

The water stored in the dam on a river has .................. .

physics structure of earth electricity from water energy hydro electricity hydro energy

  1. Kinetic energy

  2. Potential energy

  3. Electrical energy

  4. Biomass energy

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Correct Option: B
Explanation:

The water stored in the dam on a river has potential energy.
The potential energy stored in a body of water held at a given height is converted to kinetic energy (movement energy) which is used to turn a turbine and create electricity.

The tidal power plants are constructed near the mouth of ................ bays.

physics structure of earth electricity from water energy hydro electricity hydro energy

  1. $renewable$

  2. $huge$

  3. $narrow$

  4. $broad$

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Correct Option: C
Explanation:

Tidal energy of sea waves is harnessed by constructing hydro electric dams at the mouth of narrow bays along the sea coast.
Hence, The tidal power plants are constructed near the mouth of narrow bays.

The ultimate source of hydroelectric energy is :

physics structure of earth electricity from water energy hydro electricity hydro energy

  1. potential energy of water

  2. kinetic energy of water

  3. solar energy

  4. chemical energy

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Correct Option: A
Explanation:

Answer is A.

Potential energy is the energy that is stored in an object due to its position relative to some zero position. An object possesses gravitational potential energy if it is positioned at a height above (or below) the zero height.
There is potential energy stored in a water reservoir behind a dam. It is converted to kinetic energy when the water starts flowing down the penstock, from the dam. This kinetic energy is used to turn a turbine.
Hence, the source for hydro electricity power generation is potential energy of water.

Destruction of large eco-systems occurs during the harnessing of.

physics structure of earth electricity from water energy hydro electricity hydro energy

  1. geothermal energy

  2. tidal energy

  3. wind energy

  4. hydroelectric energy

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Correct Option: D
Explanation:

To harness hyrdoelectric energy large hydroelectric plants are required to be built across the streams. These plants should be of very high qulaity and are expensive to build. Dams are not only costly but they also take a toll on the environment and natural habitat near it.

Which of the following are disadvantages of hydro power plant?

physics structure of earth electricity from water energy hydro electricity hydro energy

  1. Dams can be constructed only in a limited number of places.

  2. Large areas of agricultural land and human habitation are sacrificed

  3. Methane is released contributing to green house effect

  4. All of above

Show answer
Correct Option: D
Explanation:

In hydro electric plants:

1. Dams are constructed in hilly areas, hence only a limited number of places.
2. Large areas of agricultural land and human habitation are sacrificed as they get submerged.
3. The vegetation which is submerged rots under anaerobic conditions and methane is released contributing to green house effect. 

Mark the statement which is an advantage of hydel energy.

biology structure of earth electricity from water energy hydro electricity hydro energy

  1. Water availability is free of cost.

  2. Construction of dams is an easy task.

  3. Both A and B

  4. None of the above

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Correct Option: A
Explanation:

The water required for generation hydel power is available free of cost. Construction of dams in not an easy task. It needs heavy investment.

Which of the following is not a limitation of hydel energy?

physics structure of earth electricity from water energy hydro electricity hydro energy

  1. Hydel power stations are pollution free.

  2. A vast reservoir is needed.

  3. It leads to a loss of wildlife habitat.

  4. It can be harnessed at only a few places.

Show answer
Correct Option: A
Explanation:

For running a hydel power station throughout the year, vast amount of water  is required. This demands a vast reservoir. Such a  reservoir can be made only at a few places which are geographically suitable and do not interfere with ecosystem and human habitation.

Ultimate source of hydroelectricity is the _______ .

biology structure of earth electricity from water energy hydro electricity hydro energy

  1. thermal energy

  2. solar energy

  3. hydrothermal energy

  4. wind energy

Show answer
Correct Option: B
Explanation:

Ultimate source of hydroelectricity is the energy of sunlight (solar energy). Heat energy of the sunlight evaporates water in oceans and lakes. This evaporated water goes into the atmosphere and returns back to the Earth as rain water or snow.

The minimum height required to convert the stored potential energy of water into electric energy is ____.

physics structure of earth electricity from water energy hydro electricity hydro energy

  1. $54\ M$

  2. $34\ M$

  3. $100\ M$

  4. $5\ M$

Show answer
Correct Option: B
Explanation:

The minimum height required to convent the stored potential energy of water into electric energy is $34\ M$ between the turbine and free energy of water in reservoir.

Which of the following is not an advantage of hydro energy?

biology structure of earth electricity from water energy hydro electricity hydro energy

  1. Flowing water is found everywhere. So hydro energy can be obtained easily.

  2. It is a renewable source of energy.

  3. It do not cause any pollution.

  4. All of the above.

Show answer
Correct Option: A
Explanation:

Water energy has the following advantages
a) Water energy is renewable and inexhaustible source of energy.
b) Water energy does not cause any pollution
c) Water energy is a cheap source of energy.