Question

An electric fan marked 60 watt consumes 3 units for the duration:
A. 50 hours
B. 150 hours
c. 10 hours
D. 15 hours

Answer 1

Hint: The apparent shift in the bottom of the beaker will be equal to the sum of the individual shifts caused by the kerosene and water mediums.

Formula used: Energy consumed is calculated by the formula, Energy=Power× time,

Complete step by step solution:
The power of the bulb is given which is used for a given period of time, so the unit consumed by it on a daily basis be calculated as follows,
Power consumed by electric bulb = 60 W
Unit = 3
Using formula
Energy = Power $\times$ Time
Time = Energy/Power
Time = $\dfrac{{3000}}{{60}} = 50$

Thus, 50 hours is the required answer.

Note: 1 UNIT = 1 kwh ( one kilowatt hour)
Where kilo = 1000
It simply means that if you have a 100 watt bulb and you make on it for 10 hour it consume one unit of power
100watt bulb × 10 hours = 1000 watt- hour = 1 kwh = 1 unit