Question

(ii) Calculate the energy released by an electric heater, which draws a current of 5 A at 220 V for
1 minute.​

Answer 1

Given :

Current flow = 5A

Applied pd = 220V

Time interval = 1 min

To Find :

Energy released by electric heater in the given interval of time.

Solution :

❒ First of all we need to find power consumed by electric heater.

Formula :- P = V × I

• P denotes power
• V denotes voltage
• I denotes current

By substituting the given values;

➙ P = V × I

➙ P = 220 × 5

➙ P = 1100 W

❒ Electric power is defined as the rate of energy consumed per unit time$.$

Mathematically, P = H / t

• H denotes heat energy
• t denotes time

➙ P = H / t

• t = 1min = 60s

➙ 1100 = H / 60

➙ H = 1100 × 60

➙ H = 66000 J = 66 kJ

Answer 2

$\huge\bf\mathfrak\blue{✫}$$\huge\bf\mathfrak{Required\: Answer}$

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$\bf\underline{Given :}$

• Current flow = 5A
• Applied pd = 220V
• Time Interval = 1 minute.

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$\bf\underline{To\: find :}$

• Energy released by electric heater in the given interval of time.

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$\bf\underline{Solution :}$

★ Power consumed by the electric heater.

we know that --» P = V × I

• P = power
• V = voltage
• I = current

Now, substitute the given values;

• P = V × I
• P = 220 × 5
• P = 1100 W

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★ Electric power =

$\dfrac{Rate\: of\: energy\: consumed}{Unit time}$

which is ↓

p = $\dfrac{H}{t}$

• H = Energy
• t = time

Note :- 1 minute = 60 seconds

• 1100 = H / 60
• H = 1100 × 60

Energy = 66000J

⁂ 66 kJ

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