Last seen: Jul 17, 2023
(a) Advantages of using wind energy for generating electricity: (i) It does not cause any pollution. (ii) It is available free of cost. (b) Limi...
(a) Moving air is known as wind. Wind posses kinetic energy. (b) The fast moving wind strikes the wind turbine which starts rotating. The shaft of t...
(a) Construction and working of solar cooker: A solar cooker consists of an insulated metal box or wooden box which is painted all black from inside...
(a) Advantage of producing hydroelectricity: (i) It does not cause any environmental pollution. (ii) It uses the energy of flowing water, which is...
The electricity generated from hydro power plant is known as hydro electricity. Water is collected in a reservoir at a height, so the water has pote...
Traditionally, wind energy was used through windmills to pump water from a well and to grind wheat into flour. But the traditional use has been modifi...
Traditionally, the energy of flowing water has been used for rotating the water-wheels and for driving water-mills to grind wheat to make flour. The t...
(a) The amount of solar energy received per second by one metre square area of the near earth space (exposed perpendicularly to the sun rays) at an av...
Solar cell panel consists of a large number of solar cells joined together in a definite pattern. It is used to convert solar energy into electricity....
(a) Advantage of solar cell (i) They have no moving parts and require no maintenance. (ii) They can be set up in remote and inaccessible areas. ...
(a) Solar cell is a device which converts solar energy directly into electrical energy. figure.png (b) Silicon (c) Use of solar cell:(i) To pro...
(a) Advantages of using solar cooker (i) It saves precious fules like coal, kerosene etc. (ii) It does not produce any smoke or ash. (iii) The f...
(a) Glass sheet cover. (b) A plane mirror reflector is used in a box type solar cooker so as to get a strong beam of sunlight after reflection from ...
Concave and plane mirrors are used for making solar cooker because concave mirror converges a large amount of sun’s rays at a point that is required f...
Sun is a renewable source of energy, where as fossil fuels are non-renewable sources of energy.
(a) Difference between thermal power plant and hydro power plant: (i) Thermal power plant uses non-renewable sources of energy like coal, oil or gas...
sunlight; electrical.
Let the numerator be x then denominator will be (x + 8) According to the question, (x + 17)/(x + 8 – 1) = 3/2 ⇒ (x + 17)/(x + 7) = 3/2 ⇒ 2(x +...
Let the age of Hari be 5x and Harry be 7x. 4 years later, Age of Hari = 5x + 4 Age of Harry = 7x + 4 According to the question, (5x + 4)/(7x + 4...
1. (8x – 3)/3x = 2 (8x – 3)/3x = 2 ⇒ 8x/3x – 3/3x = 2 ⇒ 8/3 – 1/x = 2 ⇒ 8/3 – 2 = 1/x ⇒ (8 – 6)/3 = 1/x ⇒ 2/3 = 1/x ⇒ x = 3/2 2. 9x/(7...