Non conventional sources of energy

Question 1

What are non conventional sources of energy ?

Answer 1

those sources of energy which have been developed in the recent past as an alternative to conventional sources

Question 2

5 Features of non conventional energy sources

Answer 2

1. Renewable
2. Inexhaustible
3. non polluting
4. less expensive
5. easy to maintain

Question 3

examples of non conventional energy sources

Answer 3

Solar energy, wind energy, tidal energy, geothermal energy, nuclear energy and bio gas

Question 4

____ is the ultimate source of energy

Answer 4

Sun

Question 5

India receives ____________ amount of solar energy

Answer 5

5000 trillion kWh

Question 6

Why does India receive high amounts of solar energy

Answer 6

it lies in tropic of cancer

Question 7

Availability of solar energy per km2 per hour in India is ___

Answer 7

5 to 7 kW

Question 8

Name three techniques used to harness solar energy

Answer 8

1. solar cells
2. solar cooker
3. Solar water heater

Question 9

Solar cells are also known as

Answer 9

Photovoltaic cells

Question 10

What are solar cells made of?

Answer 10

thin wafers of semi conducting materials like silicon and gallium

Question 11

How do solar cells work?

Answer 11

When sun’s radiation strikes them, it is converted to electricity

Question 12

Solar cells are widely used in

Answer 12

Water pumps, street lighting, traffic signals, calculators and electronic watches

Question 13

What is the purpose of a mirror in a solar cooker ?

Answer 13

It reflect the radiations onto a glass sheet which covers a black insulated box.

Question 14

Where is the raw food kept in a solar cooker?

Answer 14

Inside the black insulated box

Question 15

Why is the inside of the box painted black?

Answer 15

For efficient absorption of light

Question 16

What is done on the outside of the box and why?

Answer 16

It is insulated to prevent heat from escaping

Question 17

What radiation does the heated inside of the box emit?

Answer 17

Infra red radiation

Question 18

Why does not the infra red radiation pass through the glass?

Answer 18

Bcoz glass is opaque to it

Question 19

Instead of a plane mirror, what is better and why

Answer 19

spherical reflector

more heating effect and greater efficiency

Question 20

sunlight falls on ____________ in a water heater.

Answer 20

Flat-plate collectors

Question 21

The flat plate collectors are essentially

Answer 21

shallow rectangular trays filled with water, properly inclined to increase efficiency of collection

Question 22

The black insulated box has a _______ … what is its role( water heater)

Answer 22

black copper coil . cold water is made to flow inside

it . coil gets heated so water gets heated and flows into the tank

Question 23

What is the function of the black insulated box

Answer 23

collect and store solar heat

Question 24

Some advantages of solar energy.

Answer 24

1. It is renewable
2. can be used for diverse purpose
3. don’t require lot of maintenance
4. saves fossil fuels
5. produce electricity - reduce bills

Question 25

wind energy is obtained using

Answer 25

windmills

Question 26

How exactly do windmills work?

Answer 26

blades of windmill rotate due to force of wind. the rotational motion drives water pumps, generators, flourmills etc...

Question 27

What are wind farms?

Answer 27

A number of windmills are installed in a definite pattern in clusters called wind farms

Question 28

three regions where generally wind farms are present

Answer 28

coastal, open grassland and hilly regions

Question 29

which country produce the most amount of wind energy

Answer 29

China

Question 30

largest wind cluster in india

Answer 30

From nagarcoil to Madurai

Question 31

advantages of wind energy

Answer 31

1. renewable 2. reduce electricity bills 3. reduce dependence on fossil fuels 4. cleanest form of renewable energy

Question 32

What is tide?

Answer 32

periodic rise and fall of waters of the ocean due to attraction of moon and sun

Question 33

What is tidal energy?

Answer 33

the rise and fall of water produces lot of energy called tidal energy

Question 34

How can the tidal energy be harnessed?

Answer 34

constructing a tidal barrage

Question 35

How does the harnessing of tidal energy work?

Answer 35

During high tide, sea water flows into the reservoir of barrage and turns turbine, which produces electricity by rotating generators. During low tide, the sea water inside the reservoir flows out during which it rotates the turbines

Question 36

Prospective sites for exploitation of tidal energy are

Answer 36

Gulf of Kutch, Cambay, Sundarbans

Question 37

advantages of tidal energy

Answer 37

1. easy to harness- rise and fall is predictable 2. inexhaustible 3. no carbon emissions 4. require very little maintenance 5. can be produced even if water moves at low speed