Question

3. An electric iron a, resistance 20 Ω takes a current of 5 A Calculate the

heat developed in 30 s.​

Answer 1

GIVEn

An electric iron a, resistance 20 Ω takes a current of 5 A

TO FINd

Calculate the heat developed in 30 s.

SOLUTIOn

Apply this formula

H = I²RT

• I = 5A
• R = 20 Ω
• T = 30 s

→ H = I²RT

→ H = (5)²×20×30

→ H = 25 × 600

→ H = 15000 Joules

According to Jolues law of heating

(★) This law can be stated as the amount of heat produced in a conductor is

a) directly proportional to the square of current flowing through it

b) directly proportional to the resistance of the conductor

c) directly proportional to the time

Answer 2

Answer:

R = 20 Ω

I = 5 A

t = 30 s

H = I^2Rt

= (5)^2×20×30

= 15000 J

= 1.5 × 10^4 J

Explanation: