Tag: physics

Questions Related to physics

A convex and a concave lens separated by distance $d$ are then put in contact. The focal length of the combination

physics lens technical terms related to lens terms related to lenses introduction to lenses and its types

  1. Decreases

  2. Increases

  3. Becomes $0$

  4. Remains the same

Show answer
Correct Option: A
Explanation:

$\dfrac{1}{f _r}=\dfrac{1}{f _1}+\dfrac{1}{f _2}-\dfrac{d}{f _1f _2}$

So when are brought in contact $d=0$, hence focal length $f _r$ will decrease .

Energy potential from various sources of sea is ____. Efficient commercial exploitation of same is _______.

physics sources of energy wave energy tidal energy wave power and tidal power

  1. Small, difficult

  2. Large, difficult

  3. Small, easy

  4. Large, easy

Show answer
Correct Option: B
Explanation:

The energy potential from the sea (tidal energy, wave energy and ocean thermal energy) is quite large, but efficient commercial exploitation is difficult.

Full form of OCTEC is:

physics sources of energy wave energy tidal energy wave power and tidal power

  1. Ocean Thermal Energy Conversion Power Plant.

  2. Ocean Thermal Consumer Energy Power Plant.

  3. Ocean Current Thermal Energy Cycle.

  4. Ocean Current Thermal Electric Plant.

Show answer
Correct Option: A
Explanation:

OCTEC stands for ocean thermal energy conversion power plant. It is a device used to harness tidal energy to produce electricity.

Rise of ocean level is called ________ and fall of ocean level is called ________

physics sources of energy wave energy tidal energy wave power and tidal power

  1. high wave, low wave

  2. low wave, high wave

  3. high tide, low tide

  4. low tide, high tide

Show answer
Correct Option: C
Explanation:

Tide  are the rise and fall of sea levels caused by the combined effects of gravitational forces exerted by the Moon, Sun and rotation of the Earth. The effect of moon is most prominent among all the factors. Rise of ocean level is called high tide and fall of ocean level is called low tide.

If ocean thermal energy is made feasible and cheaper, it has tremendous potential because:

physics sources of energy wave energy tidal energy wave power and tidal power

  1. Potential energy in oceans is immense

  2. Ocean waves are very strong

  3. Most of the solar energy is incident on the ocean surface

  4. A lot of heat energy is trapped in the land mass below the oceans

Show answer
Correct Option: C
Explanation:

$71 \%$ of the Earth's surface is covered by oceans. Hence, most of the solar energy is absorbed by the oceans. This energy can be harnessed using OCTEC. Hence, ocean thermal energy has great potential.

From below which is the type of energy from sea?

physics sources of energy wave energy tidal energy wave power and tidal power

  1. Tidal Energy

  2. Wave Energy

  3. Ocean Thermal Energy

  4. All of above

Show answer
Correct Option: D
Explanation:

Energy from the sea can be classified into three types:

1. Tidal energy - This energy is harnessed by building a dam and placing a turbine near the opening of the dam. By using the turbine, tidal energy of the sea is used to produce electricity.
2. Wave energy - Kinetic energy of the wave is used in generation of electricity.
3. Ocean thermal energy - Thermal difference between the cold ocean water and warm tropical surface water is used to generate electricity.

What is known as Ocean thermal energy?

physics sources of energy wave energy tidal energy wave power and tidal power

  1. The Sun's heat warms the surface water a lot more than the deep ocean water which creates ocean's naturally available temperature gradient.

  2. The Moon's heat warms the surface water a lot more than the deep ocean water which creates ocean's naturally available temperature gradient.

  3. The Solar cell's heat warms the surface water a lot more than the deep ocean water which creates ocean's naturally available temperature gradient.

  4. None

Show answer
Correct Option: A
Explanation:

Temperature gradient of the water with deep ocean being cold and tropical surface water being warm due to the Sun's heat is the ocean thermal energy.

What are built near seashores to collect water which comes during high tide?

physics sources of energy wave energy tidal energy wave power and tidal power

  1. Dams or reservoirs

  2. Solar panel

  3. Wind mill

  4. Water well

Show answer
Correct Option: A
Explanation:

Dams or reservoirs are usually build near the narrow opening of the seashores to harness the energy of the waves during high tide in generation of electricity.

Waves are used to rotate ____________ to generate electricity. Fill in the gap.

physics sources of energy wave energy tidal energy wave power and tidal power

  1. Rotor of Dynamo

  2. Turbine of dam

  3. Wheel of wind mill

  4. Armature of motor

Show answer
Correct Option: A
Explanation:

Waves are made to fall from a height on to the rotor of a turbine or dynamo to make them rotate. This mechanical energy is then converted to electrical energy.

The two different ways of harnessing energy from ocean are :

physics sources of energy wave energy tidal energy wave power and tidal power

  1. Tidal Wave, OTEC

  2. Geothermal, wave energy device

  3. Solar energy, point wave absorber

  4. All of the above

Show answer
Correct Option: A
Explanation:

The two different ways of harnessing energy from ocean is Tidal wave and Ocean Thermal Energy Conversion (OTEC).
Answer (A) Tidal Wave, OTEC