What is the primary purpose of earthing in an electrical installation?

• To reduce voltage

• To prevent electric shock

• To increase circuit resistance

• To regulate current

Which regulation document provides guidance on earthing arrangements in the UK?

• IEC 60364

• BS 7671

• The Building Regulations

• The IET Code of Practice

What does the term 'TN-S' indicate in earthing systems?

• The neutral and earth are separate throughout

• The installation uses a protective conductor only

• A direct connection to the supplier's neutral

• The installation is isolated from earth

In a TT system, the earth connection is typically made via:

• The supplier's neutral conductor

• An earth rod

• A metallic water pipe

• A shared earth bar

Which earthing system is commonly used in rural areas?

• TN-S

• TT

• TN-C-S

• IT

What does the term 'TN-C-S' stand for?

• Protective Earth and Neutral Combined in Supply

• Neutral and Earth Shared in the Circuit

• Combined Neutral and Earth in the Circuit Supply

• Temporary Neutral Circuit Supply

In a TN-C-S system, the PEN conductor stands for:

• Protective Earth and Neutral

• Primary Earthing Network

• Parallel Earth and Neutral

• Protective Earthing Node

Which of the following is a risk associated with a TN-C-S system?

• High earth loop impedance

• Earth potential rise

• Voltage drop

• Equipment overloading

The main earthing terminal (MET) in an installation is used to:

• Distribute electrical current

• Isolate the circuit

• Connect all protective conductors to earth

• Fuse the main supply

What is the primary function of an earth electrode?

• To reduce supply voltage

• To discharge fault currents safely to the ground

• To support the installation's neutral supply

• To control current flow in a circuit