Question

An electric bulb of 40 W is used for 50 days at 5 hours per day. Find the units of energy consumed by the bulb and the cost of using electricity at the rate Rs. 3 per unit

Answer 1

Given:-

• Power of Electric bulb = 40 W

• Used For 50 days at 5 hours per day .

• Rate of electricity = 3 Per Unit.

To Find:-

• Energy consumed by the bulb and the cost of using electricity of 50 days .

Solution:-

According to the Given Question

⟹Energy Consumed by bulb In one day = Power of Bulb × Time used for one day .

⟹ Energy Consumed = 40 × 5

⟹ Energy Consumed = 200 watt .

⟹ Energy Consumed by bulb in 50 days = 200 × 50

⟹ Energy Consumed by bulb in 50 days = 10000 watt hour.

As we know that

⟹ 1 Unit = 1000 watts

Therefore 10000 watt = 10000/1000 = 10kwh

Cost of 1 Unit electricity = 3 Per unit

∴ Cost of 10 unit = 10 × 3 = Rs 30 .

Extra Information !!!

➲ The Rate at which the energy is transferred by an object is called power .

➲ SI unit of Power is Joule (J).

The mathematical relation of Power.

⟹ Power = work done /Time taken

Answer 2

✔ GIVEN :-

• Power Of Bulb = 40 W.

• Rate Of Electricity = ₹3 (per unit).

• Time = 5 hrs.

✔ TO FIND :-

• Energy consumed by the bulb in 50 days.

✔ SOLUTION :-

We know the formula that,

Energy = Power × Time.

Put the values.

Energy = 40 × 5.

So, Energy Consumed is 200 Watts.

We need to find of 50 days.

So,

Energy Consumed In 50 Days = 200 × 50

Energy Consumed In 50 Days = 10000 Watts.

So, Your Answer is :- 10000 Watts.