Transmission & Distribution of Electricity

Why is alternating current used instead of direct current in the transmission of electricity through long distances?

• Only alternating current can flow through the cables.

• Alternating current voltage can be stepped up or stepped down by using transformers.

• Most of the electrical appliances work only with alternating current.

• Generating direct current is more complicated than generating alternating current.

The function of the transformer in the transmission of electricity is to

• increase the resistance.

• change the voltage.

• reduce the time to transmit the electricity.

• increase the power.

Electricity is generated at a .......

• power station

• petrol station

• power source

• source of energy

Transformers .............. voltage for use in homes.

• step down

• step up

Electricity is sent over ............... transmission lines.

• low voltage

• no voltage

• high voltage

Function of the national grid network.

• Transmit high voltage alternating current.

• Switch off the alternating current.

• Step down the voltage of alternating current.

The efficiency of transmitting electrical power by cable through great distance can be improved by

Kecekapan penghantaran kuasa elektrik menggunakan kabel melalui jarak yang besar boleh ditingkatkan dengan

• lowering the voltage and using thick cable.

  turunkan voltan dan gunakan kabel yang tebal.

• lowering the voltage and using big current.

  turunkan voltan dan gunakan arus yang besar.

• increasing the voltage and using thin cable.

  tambahkan voltan dan gunakan kabel yang nipis.

• increasing the voltage and using thick cable.

  tambahkan voltan dan gunakan kabel yang tebal.

The example of non-renewable energy:

• coal

• natural gas

• solar

• petroleum

Choose the step-up transformer

• A

• B

• C

_______ carries electric current to an electrical appliances.

• Neutral wire

• Live wire

• Earth wire