Period 1: Transformer Equations

Transformers are important to the national grid because they allow efficient transmission of electricity over long distances by:

• Adjusting voltage levels

• Generating electricity

• Storing electrical energy

• Converting electricity to heat

A transformer changes the voltage of electricity. What does its structure include?

• Primary and secondary coils

• Batteries and wires

• Solar panels and turbines

• Switches and fuses

Define Electric Power.

• Electric Power is the rate at which electrical energy is transferred by an electric circuit. It is measured in watts (W).

• Electric Power is the amount of current flowing through a conductor regardless of voltage.

• Electric Power is the resistance offered by a material to the flow of electric current.

• Electric Power is the total charge stored in a battery.

Learning Objectives (To Be Able To...): Calculate Electric Power of a device.

• Electric Power (P) can be calculated using the formula P = V × I, where V is voltage and I is current.

• Electric Power (P) can be calculated using the formula P = V + I, where V is voltage and I is current.

• Electric Power (P) can be calculated using the formula P = V / I, where V is voltage and I is current.

• Electric Power (P) can be calculated using the formula P = I - V, where V is voltage and I is current.

Learning Objectives (To Be Able To...): Calculate Efficiency.

• Efficiency can be calculated using the formula Efficiency = (Output Power/Input Power) × 100%.

• Efficiency can be calculated using the formula Efficiency = (Input Power/Output Power) × 100%.

• Efficiency can be calculated using the formula Efficiency = (Output Power × Input Power) × 100%.

• Efficiency can be calculated using the formula Efficiency = (Output Power/Input Power) ÷ 100%.

Transmission cables in the National Grid are used to transfer electrical power from power stations to consumers.

• True

• False

What is power?

• The rate of doing work.

• The amount of force applied.

• The distance covered in a given time.

• The mass of an object.

For transformer calculations, we imagine that transformers are 100% efficient.

• True

• False

All the power supplied to the primary coil is transferred to the secondary coil.

• True

• False

If 100 W of power is supplied to the primary coil, how much power will be transferred to the secondary coil?

• 100 W

• 50 W

• 10 W

• 200 W