Question

If an electric bulb of 100 W is lighted for 3 hours daily. How much electrical energy would be consumed daily? Also find the cost if cost per unit is ₹3.​

Answer 1

Explanation:

heat is power consumptio in one second and si unit is joule sorry for the mistake above

Answer 2

Given:-

→ Power of the electric bulb = 100 W

→ Time for which it is lighted = 3 hours

→ Cost per unit = ₹3

To find:-

→ Electrical energy consumed daily.

→ Cost of electricity.

Solution:-

Firstly, let's convert the power of the bulb from W to kW.

⇒ 1 W = 0.001 kW

⇒ 100 W = 100(0.001)

⇒ 0.1 kW

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Now, we know that :-

Energy = Power × Time

Energy consumed by the bulb/day :-

= 0.1 × 3

= 0.3 kWh

Cost of electricity:-

= 0.3 × 3

= ₹0.9

Thus :-

• Energy consumed by the bulb daily is

0.3 kWh .

• Cost of electricity is ₹0.9 .

Some Extra Information:-

• kWh is the commercial unit of energy

and is used by electricity boards.

• If power is in kW and time is hour, then

the unit of energy is kWh.

• 1 kWh = 1000 W × 3600 s

= 3600000 Ws

= 3600000 J

= 3.6×10⁶ J