Question

and electric iron resistance 20 ohm takes a current of 5 a . calculate the heat developed in 0.5 minutes​

Answer 1

Answer:

$\boxed{\mathfrak{Heat \ developed \ (H) = 15 \ kJ}}$

Given:

Resistance (R) = 20 Ω

Current (I) = 5 A

Time (t) = 0.5 min = 30 s

To Find:

Heat developed (H) in the electric iron

Explanation:

Formula:

$\boxed{ \bold{ \sf H = I^2Rt}}$

Substituting values of I, R & t in the equation:

$\sf \implies H = {5}^{2} \times 20 \times 30 \\ \\ \sf \implies H = 25 \times 20 \times 30 \\ \\ \sf \implies H = 15000 \: J \\ \\ \sf \implies H = 15 \: kJ$

$\therefore$

Heat developed (H) in the electric iron = 15 kJ

Answer 2

Explanation:

An electric iron resistance 20 ohm takes a current of 5A.

We have to find the heat developed in 0.5 minutes.

Firstly convert time into seconds. To do this, multiply the given value by 60.

time = 0.5*60 = 30 sec

Using Joule's Law Heating:

H = I²Rt

Where H is heat, I is current, R is resistance and t is time.

Substitute the values in the above mentioned formula,

→ H = (5)² × 20 × 30

→ H = 25 × 600

→ H = 15000J

Hence, the heat developed in 0.5 minutes is 15000J or 15kJ.