Steel Authority Of India Limited SAIL Model Questions Electrical Engineering Questions

Steel Authority Of India Limited

SAIL Model Questions

Electrical Engineering Questions

Q. Which of the following device is used in transformer?

• Tube light
• Electric heater
• Mobile phone
• Rectifier module

Q. Earth electrodes can be in the form of

• rods or piper
• stripes
• plates
• any of above

Q. Carbon or metal brushes are used in

• DC generators only
• AC generators only
• Both AC & DC generation
• None of above

Q. Energy is lost due to Joule's heating effects in winding of transformer. This is called

• Copper loss
• Eddy current loss
• Flux loss
• None

Q. In refrigeration cycle heat is lost in

• Cooling coil
• Condenser
• Compressor
• Expansion valve

Q. The power factor of AC circuit is

• R/X
• R/Z
• Z/R
• Zero

Q. Silicon controlled output is good if ripple factor is

• Switch
• Transformer
• Amplifier
• None of above

Q. The rectifier output is good if ripple factor is\

• More
• Less
• Constant
• None of above

Q. Protective relays can monitor large AC current by means of

• Current transformer
• Potential transformer
• Micro transformer
• None of above

Q. The combines AM of two similar batteries connected in parallel is:

• halved
• doubled
• remain constant
• none of above

Q. The current in circuit having 5 V EMI source and 10 Ohm resistance is:

• 2 Amp
• 50 Amp
• 5 Amp
• ½ Amp

Q. The chopper is a device to change

• Voltage
• Current
• Frequency
• None of these

Q. The power consumption, in case of centrifugal loads (like pump, fan, blower etc) is proportional to:

• speed
• square of speed
• cube of speed
• none of these

Q. Which of these need to be measured after rewinding the motor:

• no load current
• air gap
• winding resistance
• all of the above

Q. Five percent increase in supply frequency will change the synchronous speed of motor by:

• -5%
• +5%
• -10%
• +10%

Q. Which of the following is the best inverter?

• square wave inverter
• sine wave inverter
• pure sine wave inverter
• triangular wave inverter

Q. For driving a motor in a tape recorder or record player, the motor used is generally:

• a synchronous motor
• a hydraulic motor
• an induction motor
• a dc series motor

Q. The DC motor starter used with a constant speed shunt motor is:

• 2 point starter
• 3 point starter
• 4 point starter
• 5 point starter

Q. A commutator in a DC motor converts

• AC to DC
• DC to AC
• Both AC to DC and DC to AC
• None of these

Q. Two transformers running in parallel will share the load according to their:

• leakage reactance
• pu impedance
• efficiency
• rating

Q. The size of the Earth Wire is determined by:

• the ampere capacity of the service wires
• the atmospheric conditions
• the voltage of service wires
• none of these

Q. The function of lightning arrester is:

• to limit the short circuit fault current
• to provide path to high voltage surge to earth
• to reduce arcing
• none of these

Q. Surge protector provide:

• high impedance to normal voltage
• low impedance to surge
• both (a) and (b)
• none of these

Q. Earthing is necessary to give protection against

• voltage fluctuation
• overloading
• danger of electric shock
• high temperature of conductors

Q. The primary function of fuse is to

• protect the appliance
• open the circuit
• prevent excessive current
• protect the line