Exercise-11.4 Page: 156

1. What is power?

Solution:

Power is that the rate of doing work or the speed of transfer of energy. If W is that the quantity of work wiped out time t, then power is given by the expression,

P = W/T

It is expressed in watt (W).

2. Define 1 watt of power.

Solution:

A body is claimed to possess power of one watt if it will work on the speed of 1 joule in 1 s.

That is,

One W = 1 J/1 S

3. A lamp consumes 1000 J of electrical energy in 10 s. What is its power?

Solution:

Power = Work/Time

P = W/T

Time = 10 s

Work done = Energy consumed by the lamp = 1000 J

Power = 1000/10 = 100 Js^-1 =100 W

4. Define average power

Solution:

The average Power of an agent could also be outlined because the total work done by it within the total time taken.