Correct Answer - Option 1 : 300
Concept:
Power (P): The rate of doing work is called power and it is also known as the rate of consumption of energy.
- The SI unit of power is "watt".
- 1 Watt = 1 Joule/second.
- The commercial unit of electric energy is kilowatt or the Board of Trade (B.O.T) unit.
One kilowatt-hour: It is defined as the electric energy consumed by the appliance of 1 kilowatt in one hour.
1 kilowatt-hour = 1 kilowatt × 1 hours = 1000 watt × 3600 s
1 kWh = 3600000 joules = 3.6 × 106 J
Calculation:
Given:
P = 100 W, t = 10hr, D = 30 days, Cost per unit (c) = Rs 10
Energy consumed (E) in 30 days = P × t × D
= 100 × 10 × 30
E = 30000 Wh
E = 30 kWh
Bill for electricity = E × c = 30 × 10 = Rs 300