Question

An electric bulb consumes 7.2kj of electrical energy in 2 min. what is the power of the electric bulb?

Answer 1

power of bulb is 60 watt

Answer 2

AnswEr:

GivEn:

• Electrical energy = 7.2 kJ
• Time = 2 minutes

To Find:

• Power of the Electrical bulb?

Solution:

$\\ \bullet{\boxed{\sf{ Power = \dfrac{Energy\: consumed}{Time\:taken} }}}$

Power is defined as the rate of doing work.

Here,

$\implies \sf{ Energy\: consumed = 7.2 \: kJ} \\ \\ \implies \sf{ 7.2 \times 1000 \: J} \\ \\ \implies \sf{7200 \: J}$

And,

We convert minute into seconds by multiplying by 60;

Time Taken (t) = 2 minutes

$\implies \sf{ 2 \times 60 \: seconds} \\ \\ \implies \sf{ 120 \: s}$

Putting the values;

we get,

$\implies {\sf{ Power = \dfrac{ \cancel{7200}^ { \: \: 60} \: J}{ \cancel{120} \: s} }} \\ \\ \implies \sf{ 60 \: J/s} \\ \\ \implies \sf{ 60 \: W}$

Thus,

The Power of this Electric Bulb is 60 Watts.

Extra Dose:

• $\bullet {\boxed{\sf{ Power = \dfrac{Work\:done}{Time\:taken} }}}$

• Power is the rate at which work is done or energy is consumed.