Question

calculate the work done by a electrical bulb rating 200 watt and worked for 20 minutes​

Answer 1

Given :

• Rating of eIectricaI buIb = 200 Watt
• Time given as = 20 minutes

To find :

• Work done

SoIution :

Here we have ;

⇔ Rating of eIectricaI buIb (P) = 200 watt

⇔ Time (t) = 20 minutes

                  = (20 × 60) s

                  = 1200 s

Now we know the formuIa :

⇔ Power = Work done/Time

⇒ 200 = Work done/1200

⇒ Work done = 200 × 1200

⇒ Work done = 240,000 J

⇒ Work done = (240,000/1000) kJ

⇒ Work done = 240 kJ

Therefore,

Work done by eIectricaI buIb = 240,000 J/240 kJ

Answer 2

Explanation:

Given that, power is 200 W and time is 20 minutes.

Firstly convert min into sec. To do this, multiply the value by 60.

So, the time is 20*60 = 1200 sec.

We have to find the work done by a electric bulb if it's rating is 200 W and it worked for 1200 sec.

Power is defined as work done upon time.

Power = Work done/Time

Substitute the values,

→ 200 = Work done/1200

→ 200*1200 = Work done

→ 240000 = Work done

Hence, the work done by the electric bulb is 240000 J.

To convert J into kJ. Divide the given value by 1000.

Hence, the work done by the electric bulb is 240 J.