Question

(i) A household uses two electric fans each of rating 80 W for 8 hours a day and four electric tubes each of
rating 20 W for 10 hours a day. Calculate the amount of electrical energy consumed (in joules) in the
month of June. (ANSWER IN JOULES)

(ii) Define the following terms

(a) Electric potential
(b) Conductivity
(c) Conductance
​

Answer 1

Answer:

Explanation:

i)

Energy consumed by electric fans = 80 X 8 X 2 = 1280 Wh = 1.28kWh

Energy consumed by electric tube = 20 X 10 X 4 = 800 Wh = 0.8 kWh

The total energy in one day = 1.28+0.80 kWh = 2.08kWh

Total energy in June =  2.08 X 30 = 62.4 kWh = 62.4 X 3.6 X 10 ⁶ = 224.64 X 10⁶ J

ii)

a - Electric potential is the work done per unit charge in moving a unit positive charge from infinity to the point

b - Reciprocal of resistivity is called conductivity

c - Reciprocal of resistance is called conductance