Question

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

heat developed in 30 s.​

Answer 1

Answer:

Given:

Resistance of the iron (R) = 20 Ω

Current (I) = 5 Ampere

Time (t) = 30 seconds

To Find:

Heat Produced in 30 s

Solution:

We know that,

$\red{\boxed{\boxed{\rm H=I^2Rt}}}$

Where,

H = Heat Produced

Given that,

R = 20 Ω

I = 5 A

t = 30 s

Substituting the above values in the formula

We get,

$\rm \implies H=5^2 \times 20 \times 30\;J$

$\rm \implies H=25 \times 20 \times 30\;J$

$\rm \implies H=25 \times 600\;J$

$\rm \implies H=15000 \;J$

Hence,

The Heat Produced is

15000 J

Answer 2

Answer:

1.4*10^4j

Explanation:

Given that Resistance(R) = 20 Ω, Electric current (I)= 5 A and time(t)= 30 s

Now we know that H= I2Rt

= 5×5×20×30

= 15000J=1.5×104J

∴ The heat developed in 30s is 1.5×104J