Electrical Engineering · Question Bank

DC Generators

146 of 196 questions match · page 2 of 8. Answer in your head first, then check the solution.

📘 EE Mock Board Exam

#21📜 EE Pre-Board March 2015📘 PowerhouseEasy

Lap winding is best siuited for voltage, current dc generators.

AHigh, Low

BLow, High

CHigh, High

DLow, Low

#22📜 EE Pre-Board March 2015📘 PowerhouseEasy

The dc armature winding in which the coil sides are placed a pole pitch apart is called winding.

AMultiplex

BFull-pitch

CFractional-pitch

DPole-pitch

#23📜 EE Pre-Board August 2015📘 PowerhouseEasy

In a 12-Pole duplex lap wound dc armature, each conductor can carry a current of 50 amperes. If the total armature conductor is 600, what is the rated current of the armature?

A30,000 A

B1,200 A

C600 A

D2,500 A

#24📜 EE Pre-Board March 2016📘 PowerhouseEasy

A 4 pole dc generator has a total of 600 conductors in its lap wound armature. The flux per pole is \(10^{6}\) lines. Determine the generated emf if it is driven at 2400 rpm.

A230v

B254v

C234v

D240v

#25📜 EE Pre-Board March 2016📘 PowerhouseEasy

Once residual magnetism of a shunt generator is lost, it may be restored by connecting its shunt field.

Ato earth

Bin reverse

Cto an external battery

Dto an alternator

#26📜 EE Pre-Board March 2017📘 PowerhouseEasy

With reference to armature windings, wave windings are often called __________ windings.

Acascade

Bring

Cmultiple or parallel

Dseries

#27📜 EE Pre-Board March 2017📘 PowerhouseEasy

The active length of each conductor placed in a DC generator armature is 0.4 m. The armature is rotated at a speed of 1,800 rpm in a magnetic field of average flux density 1.2 T. The diameter of the armature is 0.5 m. Find the emf induced in the conductor when it cuts the magnetic field at right angles.

A5.65 v

B11.31 v

C45.24 v

D22.62 v

#28📜 EE Pre-Board March 2017📘 PowerhouseEasy

The purpose of providing dummy coils in a generator is

Ato reduce eddy current losses

Bto enhance flux density

Cto amplify voltage

Dto provide mechanical balance for the rotor

#29📜 EE Pre-Board August 2017📘 PowerhouseEasy

In a generator, if the voltage regulation is 5.5% and the full-load voltage is 220 volts, what is the no-load voltage?

A232.1 V

B207.9 V

C225.5 V

D241.2 V

#30📜 EE Pre-Board August 2017📘 PowerhouseEasy

A 4-pole wave wound generator has 220 coils of 10 turns each. The resistance of each turn is 0.02 Ω. Find the resistance of the armature winding.

A11 Ω

B22 Ω

C44 Ω

D5.5 Ω

#31📜 EE Pre-Board August 2017📘 PowerhouseEasy

In a shunt generator the voltage builds up until constrained by

Aarmature reaction

Bfield resistance

Csaturation of iron

Dbrush drop

#32📜 EE Pre-Board August 2017📘 PowerhouseEasy

The series field of a short-shunt compound dc generator is excited by ______ current.

Aarmature

Bshunt field

Cno

Dload (line)

#33📜 EE Pre-Board March 2018📘 PowerhouseEasy

In dc machines, lap winding is used for

Ahigh voltage low current

Blow voltage low current

Chigh voltage high current

Dlow voltage high current

#34📜 EE Pre-Board March 2018📘 PowerhouseEasy

An 8-pole lap wound dc generator has 1,000 armature conductors, flux of 20 mWb per pole and emf generated is 400 v. What is the speed of the machine?

A1,000 rpm

B1,800 rpm

C1,200 rpm

D1,500 rpm

#35📜 EE Pre-Board March 2018📘 PowerhouseEasy

The number of parallel paths in a simplex lap winding is equal to

Bnumber of poles

Cnumber of pairs of poles

#36📜 EE Pre-Board August 2018📘 PowerhouseEasy

A 4-pole wave wound generator has 220 coils of 10 turns each. The resistance of each turn is 0.02 Ω. Find the resistance of the armature winding.

A11 Ω

B22 Ω

C0.2 Ω

D0.44 Ω

#37📜 EE Pre-Board August 2018📘 PowerhouseEasy

How many commutator bars does a 6-pole dc generator with 4 coil sides per slot and 20 slots per pole have?

A60

B120

C240

D480

#38📜 EE Pre-Board August 2018📘 PowerhouseEasy

The dummy coil in dc machines is used to

Aeliminate reactance voltage

Beliminate armature reaction

Cbring about mechanical balance of armature

Deliminate harmonics developed in the machine

#39📜 EE Pre-Board August 2018📘 PowerhouseEasy

An 8-pole triplex wave-wound armature carries a total of 660 amperes. If there are 8 brush arms, calculate the current in each armature conductor.

A110 A

B66 A

C22 A

D11 A

#40📜 EE Pre-Board August 2018📘 PowerhouseEasy

Residual magnetism is necessary in a

Aseparately excited generator

Bself-excited generator

Cboth of these

Dnone of these

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