Topology

In a domestic situation, a downstairs power socket and an immersion heater respectively, are usually wired as:

• both radial circuits

• both ring circuits

• a radial and a ring

• a ring and a radial

Select the correct statement about a ring system:

• converting a radial system to a ring means cable sizes can be smaller

• less expensive

• no alternative supplies available

• cable sizes will be increased

Select the correct statement regarding a radial sysem :

• cable sizes are smaller than a ring

• when a fault develops all consumers on the circuit lose their supply

• the terminal consumer voltage is unaffected by other consumers

• fault finding is difficult

The per-unit expression for efficiency is:

• P_input ÷ P_output

• P_INPUT ÷ (P_OUTPUT - P_LOSS)

• (P_OUTPUT - P_LOSS) ÷ P_INPUT

• (P_INPUT - P_LOSS) ÷ P_INPUT

Select the correct current sharing equation:

• 
• 
• 
• 

Select the correct statement regarding a domestic kitchen ring socket circuit:

• wherever a kettle is plugged in, the current will flow from two directions

• whenever a kettle is plugged in, the current will only flow down the shortest route

• a faulty kettle would only cause half the circuit to be disconnected

• switching on a kettle and toaster would cause the fuse to blow