Question

A grinder of power 750w works for 2hrs.
Calculate the energy consumed​

Answer 1

Data Given: Power = 750 W, ... Solution: Energy consumed = Power Rating x time of operation. Therefore, Energy consumed = 750 W x 2 hrs x 30 days = 45000 W hour. Therefore, Energy consumed = (45000 / 1000 ) kWh

Answer 2

Given:

A grinder of power 750w works for 2hrs.

To Find:

The energy consumed.

Solution:

To find the energy consumed we will follow the following steps:

As we know,

Power is defined as energy per unit of time.

And, a unit of power is a watt or joule per second or joule per hour.

The formula for finding power =

$\frac{energy}{time}$

Now,

Energy = power × time = 750 × 2 = 1500 watt-hour.

Converting watt-hour to watt-second or joule.

1 hour contains 60 minutes and 1 minute contains 60 seconds.

So,

Energy = 1500 × 60× 60 seconds = 5400000 joule or 5400 KJ.

Henceforth, the energy consumed is 5400 KJ.