Question

Electric heater draws a current of 5A and its element has resistance of 50 ohm. if the heater is switched on for 5 minutes.calculate the energy released by the heater in KJ.

Answer 1

Explanation:

I = 5A

R= 50Ω

t = 5min = 5×60s = 300s

:. Energy released =I²Rt

       =5²x50x300

              =3,75,000 J

              = 375 KJ

Answer 2

Given:

• Current = 5 Ampere
• Resistance of heater = 50 ohm
• Time taken = 5 minutes

To find:

• Energy released by heater in kJ?

Calculation:

The general expression for heat output in a circuit is :

$\boxed{H = {i}^{2} \times r \times t}$

• 'i' is current, 'r' is resistance and 't' is time.

First of all, lets convert the necessary values in SI UNITS :

• 5 minutes = 5 × 60 = 300 sec

Now, putting the values :

$\implies H = {5}^{2} \times 50 \times 300$

$\implies H = 375000 \: joule$

$\implies H = 375\:kilo joule$

So, heat output by heater is 375 kJ.