ELECTRICAL MACHINE TEST

JavaScript isn't enabled in your browser, so this file can't be opened. Enable and reload.

ELECTRICAL MACHINE TEST_02

DC GENERATOR

Q.01 A machine which converts mechanical energy into electrical energy is called

1 point

motor

generator

transformer

all of the

Clear selection

Q.2 In DC generator which of the following is true?

1 point

It converts mechanical energy into AC electrical energy

It converts AC electrical energy into DC electrical energy

It converts mechanical energy into DC electrical energy

It transfer electrical energy from one circuit to other

Clear selection

Q.3 A DC generator is operated on ___

1 point

statically induced emf

self induced emf

mutually induced emf

dynamically induced emf

Clear selection

Q.4 Which of the following is/are necessary to produce emf?

1 point

magnetic field

all of given

conductors

motion of conductors w.r.t magnetic field

Clear selection

Q.5 A rotating machine has mainly ___

1 point

three parts, stator and rotor, separated by an air gap

two parts, rotor, separated by an air gap

two parts, stator and separated by an air gap

two parts, stator and rotor

Clear selection

Q.6 The winding in which voltage is induced is called the ___

1 point

field winding

rotor winding

armature winding

none of the above

Clear selection

Q.7 The DC generator is based on the principle that a conductor is rotated in ____, a voltage will be generated n the conductor

1 point

none of given

electrostatic field

magnetic field

electric field

Clear selection

Q.8 In small machine yoke is made up of

1 point

cast steel

cast iron

wrought iron

mild steel

Clear selection

Q.9 Poles of modern small dc machine is made up of __

1 point

sheet of copper

sheet steel

iron steel

alluminium sheet

Clear selection

Q.10 122 The thickness of lamination of sheet steel of pole core is about__

1 point

1.5 to 2.5 mm

2.0 to 2.5 mm

1.0 to 2.5 mm

1.0 to 1.5 mm

Clear selection

Q.11 The poles are laminated to reduce___

1 point

iron loss

copper loss

eddy current loss

hysteresis loss

Clear selection

Q.12 The ends of the field coil are brought out to the ____

1 point

commutator connection

brush

load connection

terminal box of the machine

Clear selection

Q.13 In a small machines the laminations are ___ to the shaft.

1 point

keyed

soldering

bolts

rivets

Clear selection

Q.14 Armature is made up of silicon steel because

1 point

it reduce the copper loss

Both C and D

it reduce the hysteresis loss

it reduce the eddy current loss

Clear selection

Q.15 Wave winding is suitable for ___

1 point

high voltage

low voltage

low current

all of the above

Clear selection

Q.16 why lap winding is used for large current machine?

1 point

none of the above

it gives more parallel path

it parallel path is equal to poles

it gives less parallel path

Clear selection

Q.17 The commutator is rotate with___

1 point

armature

stator

poles

bearing

Clear selection

Q.18 current is collected from the armature winding by means of two or more ____

1 point

brushes

terminals

windings

all of the above

Clear selection

Q.19 Brushes is made up of ___

1 point

carbon

graphite

aluminium

Both A or B

Clear selection

Q.20 What is the function of bearing?

1 point

to support the rotating armature

to reduce the friction

it transfer the mechanical energy to shaft

Both A and B

Clear selection

Q.21 The conductors are connected is series for ____

1 point

current rating of machines

voltage rating of machines

torque producing capacity

none of the above

Clear selection

Q.22 A type of generator whose field winding is not excited by the external source but its own source is called ___

1 point

separately excited dc generator

self excited dc generator

Ac generator

none

Clear selection

Q.23 The field current of shunt field generator is__

1 point

remains almost constant

almost variable

depend on load current

can't defined

Clear selection

Q.24 Calculate the generated emf of a 240V shunt generator supplies power to the load having resistance of 1.2 ohm. Resistance of the shunt field and armature winding are 120ohm an d0.008ohms respectively.

1 point

245.16 V

256.16 V

260 V

260.16 ohm

Clear selection

Q.25 Why the resistance of series field winding is kept very low?

1 point

to increase the voltage drop across it

to decrease the voltage drop across it

to increase the load current

to increase the excitation

Clear selection

Submit

Clear form

Forms

This content is neither created nor endorsed by Google.