Question

1.A radio set is rated 200W,240V explain the meaning of the statement
An electric kettle connected to a 240 V mains supply draws a current of 8A.calculate
a.the power of the kettle
b.the energy dissipated in 10 minutes

Answer 1

The power is 1920 J and the energy dissipated in 10 minutes is E = 1, 152 KJ

Explanation:

We are given that:

• Voltage "V" = 240 V
• Current "I" = 8 A
• Time "T" = 10 min = 600 sec

To find:  

• (a) Power of kettle
• (b) Energy transferred in 10 min

We know that:

P = VI

So,

(a) P = 240 X 8

P = 1920 J

(b) We know that energy = P X T

T = 10 min = 600 sec

So,

E = 2300 X 60 0

E = 1,152,000 J

E = 1, 152 KJ

Thus the power is 1920 J and the energy dissipated in 10 minutes is E = 1, 152 KJ