Electrical Power

Question 1

Define Energy.

Answer 1

Energy is generally defined as the ability to do work or cause change.

It can exist in various forms, such as potential, kinetic, thermal, electrical, chemical, and nuclear, and can be transformed from one form to another.

Question 2

Define Work.

Answer 2

Transfer of energy from one form to another.

Question 3

Define Power and express it as a mathematical equation.

Answer 3

Power is denied as the rate of doing work or expending energy.

P = W / t

Question 4

What are the three basic power equations we can use in the electro technology industry?

Answer 4

P = I^{2 R}

P = V^{2 / R}

P = V.I

Question 5

What are the three basic current equations we can use in the electro technology industry?

Answer 5

Amps = volts / ohms

Amps = watts / volts

Amps = square root of (watts / ohms)

Question 6

What are the three basic Volt equations we can use in the electro technology industry?

Answer 6

Volts = square root of (watts x ohms)

Volts = watts / amperes

Volts = amperes x ohms

Question 7

What are the three basic resistance equations we can use in the electro technology industry?

Answer 7

Ohms = volts / amperes

Ohms = volts² / watts

Ohms = watts / amperes²

Question 8

What is the relationship between power, voltage and current?

Answer 8

P=V.I
Power is proportional either to Volts squared or Amps squared.

Question 9

What is a ‘power rating’ and what happens if it is exceeded?

Answer 9

The power rating is the maximum rating for a resistor or any electrical device.

If it is exceeded, it can overheat and/or fail.

Question 10

Name 2 ways that the power of an electrical circuit can be measured.

Answer 10

Watt meter or a watt meter and amp meter together.

Can also be calculated with P = I.V