Advertisements
Advertisements
Question
What are the advantages and disadvantages of using solar cells for producing electricity?
Advertisements
Solution
Advantages of Solar Cells:
(i) Solar cells have no moving parts, easy to construct, require little maintenance.
(ii) Solar cells derive their energy from solar radiation which is a renewable source of energy and also inexhaustible.
(iii) They are most suitable for the remote inaccessible and isolated places where laying a power transmission line may be expensive and not commercially viable.
(iv) They are environmentally friendly as they do not cause any pollution.
(v) Use of solar cells enables us to save the usage of fossil fuels as solar cells require no fuel.
Disadvantages of Solar Cells:
(i) The manufacturing cost of solar cells is sufficiently expensive.
(ii) The efficiency of energy conversion of solar energy to electricity is low.
(iii) The electricity produced in solar cells is direct current (DC) which cannot be directly used for many household appliances.
RELATED QUESTIONS
Differentiate between energy and power.
A cricket ball is thrown up from the earth's surface. What happens to its P.E.
(a) during the motion
(b) at the highest point?
(a) Define power and name its unit.
(b) A girl weighting 50 kg climbs up 60 steps each of 20 cm height in 5 minutes. Calculate the power developed.
Fill in the boxe to show the corresponding energy transformation.
Fill in the boxe to show the corresponding energy transformation.
State the energy changes which take place when A piece of magnesium wire is burnt in a jar of oxygen.
How much energy is gained by a box of mass 20 kg when a man, runs carrying the box with a speed of 3 m/s-1 to catch the bus?
A truck driver can load oil drums into the back of the truck by pushing them up a sloping plank, or by lifting them directly. Each drum has a mass of 80 kg, the plank is 3 m long, and the back of the truck is 0.8 m above the ground.
(i) How much force would be needed to lift a drum into the truck directly/without using the plank? (Take g = 10 m/s2)
(ii) How much energy would be required in lifting the drum into the truck without the plank?
(iii) If the force needed to push the drum up the plank is 300 N, why is this less than the answer to part (i)?
(iv) When the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck.
(v) The driver has to stop at the factory gates. What happens to the kinetic energy of the truck?
A coolie is pushing a box weighing 1500 N up an inclined plane 7.5 m long on to a platform, 2.5 m above the ground.
(i) Calculate the mechanical advantage of the inclined plane. (ii) Calculate the effort applied by the coolie.
(iii) In actual practice, the coolie needs to apply more effort than what is calculated. Give one reason why you think the coolie needs to apply more effort.
