Electrical Systems and Design Quiz

A three-phase electrical supply is preferred in large buildings primarily because it:

• Consumes less power

• Requires fewer wires

• Distributes load more efficiently

• Eliminates the need for protective devices

If an electrical installation requires protection against both overload and short circuit, which protective device is the most suitable?

• Miniature Circuit Breaker (MCB)

• Residual Current Circuit Breaker (RCCB)

• Rewireable fuse

• Lightning arrester

Which type of earthing is most appropriate for a multi-storey building to ensure safety and compliance with ISI standards?

• Pipe earthing

• Plate earthing

• Strip earthing

• Rod earthing

Why is a Residual Current Device (RCD) used in residential buildings?

• To prevent overload

• To protect against short circuits

• To detect leakage current and prevent electric shock

• To regulate voltage

The choice of switchgear in a building substation depends on:

• The voltage level and fault current rating

• The distance between distribution boards

• The availability of power from the grid

• The number of transformers installed

In a large office complex, which wiring system is best suited for accommodating future expansions?

• Cleat wiring

• Surface conduit wiring

• Casing and capping wiring

• Concealed conduit wiring

In the event of a fire in a building, which type of wiring offers the best safety?

• PVC insulated wiring

• Polyethylene insulated wiring

• Mineral-insulated copper-clad (MICC) wiring

• Rubber-insulated wiring

While planning the electrical layout of a residential building, which of the following would be a violation of ISI standards?

• Providing separate circuits for lighting and power

• Using different earthing for power and lighting circuits

• Installing sockets without proper earthing connection

• Using copper conductors for electrical wiring

Which factor has the greatest impact on the visual performance of a task?

• The reflectance of the surrounding walls

• The contrast between the task and its background

• The color temperature of the light source

• The position of the observer

Why is luminous efficiency an important parameter in lighting design?

• It indicates how much of the electrical power is converted into visible light

• It determines the weight of the lighting fixture

• It defines the number of light sources required in a space

• It affects the depreciation factor of the luminaire