1. It’s a good practice to connect ground wire for a building electrical system to a _pipe

Steam

Gas

Cold water

Vent

2. A co2 fire extinguisher is specifically useful for putting out fires started by

Oily rags

Paper

Electricity

Dry wood

3. Differential relays are installed to protect the equipment against

Reverse current

Internal faults

Over currents

No voltage

4. The letters T.P.D.T. identify a

Conduit

Switch

Thick wire

Fuse

5. Charging current in a transmission line

Increase line losses

Decrease line losses

Increase the line current

None of above

6. Which of the following generating station has the minimum running cost?

Hydro-electric

Nuclear power

Thermal power

Diesel

7. An electric motor in which rotor and stator field rotate simultaneously is called a_ motor

Dc

Induction

Synchronous

Universal

8. In an efficient transformer, the energy transferred from input to output

Is 100%

Is above 90%

Depend on turn ratio

Depend on core area

9. Power failure relays operate in most stand by power installations when the normal phase voltage falls to _ percent

95

80

70

50

10. Three phase alternator are invariably Y - connected because

Magnetic losses are the minimum

Less turns of wire are required

Smaller conductors can be used

Higher terminal voltage is obtained