Every day, we use electric power to run our modern appliances. Electric power transmission lines are visible examples of transportation of electricity. Power is the rate at which energy of any type is transferred. The factors that determine the consumption of electric power are both current as well as voltage. Our society depends on electricity. Using it more efficiently will mean that impact of our natural resources can be reduced.
In a domestic circuit as shown in the figure below, A room has a ceiling fan, a tube light and a filament bulb. The tube light draws 40 W, the fan 120 W and the bulb draws 60 W on an average. The tube light is kept on for 6 hours, the fan for 12 hours and the bulb for 5 hours a day. The rate of electrical energy consumed is 3.5 rupees/ unit.
i) How many units of energy are consumed only by the fan for a day?
a) 144
b) 1.44
c) 14.4
d) 0.144
ii) Identify the correct statement about the combination of the three electrical components:
a) All three are in series and applied potential across each component remains same.
b) All three are in parallel and current through each component remains same.
c) All three are in parallel and applied potential across each component remains same.
d) All three are in series and current through each component remains same.
iii) What should be the characteristics of the material used for making the safety device used to protect these appliances?
a) It should have high melting point and high resistivity.
b) It should have high melting point and low resistivity.
c) It should have low melting point and high resistivity.
d) It should have low melting point and low resistivity
iv) Which among the following equation cannot be used to calculate electric power.
a) P= VI
b) P = V2 / R
c) P = I2 R
d) P= I2 / R
v) If two more bulbs of power 80 W and 100 W are included parallel to the 60 W bulb, which bulb will consume more energy?
a) 80 W
b) 60 W
c) 100 W
d) All the bulbs will consume same energy