Electrical energy equation

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Electrical energy equation
Electrical energy equation | Image: Learnool

The electrical energy equation, expressed as E = P × t, establishes a relationship between the electrical energy (E) consumed or produced by a device, the electrical power (P) at which it operates, and the duration of operation (t). By using this equation, one can calculate the amount of electrical energy consumed or produced by a device based on its electrical power and the duration of operation.

Practice problems

Problem #1

Calculate the electrical energy consumed by a 60 W electric bulb when it is switched ON for 5 minutes.

Solution

Given data:

  • Electrical power, P = 60 W
  • Time, t = 5 minutes = 300 s
  • Electrical energy, E = ?

Applying the formula:

  • E = P × t
  • E = 60 × 300
  • E = 18,000 J

Therefore, the electrical energy used by an electric bulb is 18,000 J.

Problem #2

A 50-inch LED TV with a power rating of 100 W operates for 20 minutes. Determine the electrical energy consumed by the television.

Solution

Given data:

  • Electrical power, P = 100 W
  • Time, t = 20 minutes = 1200 s
  • Electrical energy, E = ?

Applying the formula:

  • E = P × t
  • E = 100 × 1200
  • E = 120,000 J

Therefore, the electrical energy used by a LED TV is 120,000 J.

Problem #3

Calculate the electrical energy used by a 500 W microwave oven that operates for 10 minutes.

Solution

Given data:

  • Electrical energy, E = ?
  • Electrical power, P = 500 W
  • Time, t = 10 minutes = 600 s

Applying the formula:

  • E = P × t
  • E = 500 × 600
  • E = 300,000 J

Therefore, the electrical energy used by a microwave oven is 300,000 J.

Problem #4

What is the amount of electrical energy consumed by a 1000 W water heater when it is turned ON for 6 minutes?

Solution

Given data:

  • Electrical energy, E = ?
  • Electrical power, P = 1000 W
  • Time, t = 6 minutes = 360 s

Applying the formula:

  • E = P × t
  • E = 1000 × 360
  • E = 360,000 J

Therefore, the electrical energy used by a water heater is 360,000 J.

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Deep

Learnool.com was founded by Deep Rana, who is a mechanical engineer by profession and a blogger by passion. He has a good conceptual knowledge on different educational topics and he provides the same on this website. He loves to learn something new everyday and believes that the best utilization of free time is developing a new skill.

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