Electrical Engineering Quiz

The type of fault which occurs when a phase conductor comes in contact with a neutral conductor is called

• An earth loop fault

• A short circuit fault

• A catastrophic fault

• An overload fault

The energy requirement for an industrial application is 1000kWh. If heat losses account for 20%, then the total energy to be supplied is?

• 1200 kWh

• 800 kWh

• 1250 kWh

• 750 kWh

The outer sheath is a crucial part of any electrical cable. Which role does it play?

• Prevent the moisture from entering the cable

• Provide the strength of the cable

• Avoid the chances of the rust on the strands

• Provide proper insulation and mechanical protection

If you were assigned to replace a faulty coil in electric water heater rated 4800W and supplied with single phase power 240V, what will be the ohmic value of the coil.

• 60 ohms

• 120 ohms

• 12 ohms

• 240 ohms

Which of the following is an advantage of higher transmission of voltage?

• Power transfer capability of the transmission line is increased

• Transmission line losses are reduced

• Area of cross section and volume of the conductor is reduced

• All of the above.

The Earthing System illustrated in Figure 1 below would be identified as a

• TN-S

• TT

• TN-C-S

• IT

The minimum value of Insulation Resistance for a 230Volt system must be

• (a) >0.25 MΩ

• >0.5 MΩ

• >1.0 MΩ

• >2.0 MΩ

A RCBO offers protection against

• short circuit current

• short circuit and earth fault current

• short circuit and overload current

• basic contact

A polarity test would be conducted to verify

• every fuse and single pole device is connected in the line conductor only

• there is sufficiently low resistance to operate the protective device within its limits

• there is sufficient circuit protection

• there is no breakdown of the conductor insulation

When performing an insulation resistance test on an 230V system, what should the test voltage be?

• 50V

• 24V

• 500V

• 250V