A heater operates with a current of 5 A and a voltage of 220 V... | General Science MCQ | Examoogle

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General SciencePhysics: Electricity

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A heater operates with a current of 5 A and a voltage of 220 V. What is the electrical energy consumed in 10 minutes?

66,000 Joules

11,000 Joules

660,000 Joules

1,100 Joules

Correct Answer

⚙️ TE • Technical Concept & PrincipleGeneral SciencePhysics: Electricity

Option C

660,000 Joules

Quick Summary:

Electrical energy is the product of power and time. Since power is the product of voltage and current, the total energy consumed is calculated by $E = V \times I \times t$ .

🔬SCScience SolutionConcept & Principle

💡 Explanation

Electrical energy is the product of power and time. Since power is the product of voltage and current, the total energy consumed is calculated by $E = V \times I \times t$ .

💡 Everyday Analogy (Real-World Intuition)

Think of electrical energy like filling a tank: Voltage is the water pressure, current is the flow rate, and time is how long you leave the tap running; the total water in the tank is the total energy used.

🧠 Memory Mnemonic / Shortcut Aid

VIT: Energy $E = V \times I \times t$

🔢 Key Formulas

$P = V \times I$ — Electrical power formula

$E = P \times t$ — Electrical energy formula

$E = V \times I \times t$ — Combined energy formula

⚙️ Working Principle

The principle of electric heating relies on Joule's law of heating. When current $I$ flows through a device of resistance $R$ under a potential difference $V$ , the electrical energy converted into other forms (primarily heat) is determined by the duration $t$ of the current flow. Here, $E = P \times t = (V \times I) \times t$ .

📌 Key Points

▸
SI unit of energy is the Joule ( $J$ ), which equals $1 \text{ Watt} \times 1 \text{ second}$ .
▸
Time must be converted from minutes to seconds: $10 \text{ min} = 10 \times 60 \text{ s} = 600 \text{ s}$ .
▸
The calculation is $E = 220 \text{ V} \times 5 \text{ A} \times 600 \text{ s} = 660,000 \text{ J}$ .

✅ Advantages

▸
Allows accurate calculation of electricity consumption for billing.
▸
Helps in selecting appropriate fuses and wiring for electrical appliances.

🛠️ Applications / Uses

▸
Calculation of electricity bills in households.
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Designing heating elements for kitchen appliances.

📄 Additional Information

▸
The constant of proportionality for power is $1$ in DC circuits.
▸
Option A results from forgetting to convert minutes to seconds ( $220 \times 5 \times 10 = 11,000$ , then multiplying by 6 mistakenly or using wrong units).
▸
Option B results from failing to convert minutes to seconds ( $220 \times 5 \times 10 = 11,000$ J).

📊 Diagram / Illustration

✅

C is correct — The total energy consumed is $660,000$ Joules obtained by multiplying $220 \text{ V}$ , $5 \text{ A}$ , and $600 \text{ s}$ .

Core Concepts Used

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Electric Power Electric Energy Time Conversion

💡 EXAM TIP

Always ensure time is in seconds when calculating energy in Joules, as the Watt is defined as Joules per second.

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