Question

the filament of an electric iron has 50 ohm resistance, how much heat in calories will be produced by it in one minute, if electricity is supplied at 200 volt ??​

Answer 1

Given that,

Resistance = 50 ohm

Time = 1 min

Voltage = 200 Volt

We need to calculate the heat

Using formula of heat

$H=\dfrac{V^2t}{R}$

Where, V = voltage

R = resistance

t = time

Put the value into the formula

$H=\dfrac{200^2\times60}{50}$

$H=48000\ J$

We need to calculate the heat in calories

Using formula for calories

$1\ cal\ of\ heat = 4.2\ J$

$48000\ J\ of\ heat=\dfrac{48000}{4.2}\ cal$

$Heat= 11.428\ kcal$

Hence, The heat produced by it will be 11.428 kcal

Answer 2

Given:

Resistance, R = 50 ohm

Voltage, V = 200 V

Time, t = 1 minute = 60 seconds

To Find:

The amount of heat in calories that will be produced by the filament in one minute.

Calculation:

- The heat produced by filament can be calculated as:

H = V²t/R

⇒ H = (200)² × 60/ 50

⇒ H = 48000 J

⇒ H = 48000/4.2 calories

⇒ H = 11428.57 cal ≈ 11.43 Kcal

-So, the heat produced by the filament in 1 minute is about 11.43 Kcal.