# Electrical Fundamentals Quiz Exam!

52 Questions | Total Attempts: 444  Settings  .

• 1.
Which of the following circuit elements stores energy in the electromagnetic field?
• A.

condenser

• B.

Inductance

• C.

Resistance

• 2.
The property of a coil by which  a  counter emf is induced  in it,when the current  through the coil changes, is known as
• A.

Self - inductance

• B.

Mutual Inductance

• C.

Series aiding inductance

• 3.
An alternator  converts ______ energy into ____energy.
• A.

Potential to kinetic

• B.

Mechanical to electrical

• C.

Electrical to mechanical

• 4.
In a single-phase alternator all four stator coil groups are connected in series so that the voltage induced in each winding add to give a total voltage that is ______ times the voltage in any one winding.
• A.

Three

• B.

Double

• C.

four

• D.

None

• 5.
For  a frequency of 400 Hz , the time period shall be
• A.

0.25 seconds

• B.

0.0025 seconds

• C.

0.025 seconds

• D.

0.005seconds

• 6.
The  period of a wave is
• A.

None

• B.

Time required to complete one cycle

• C.

Expressed in amperes

• D.

Same as frequency

• 7.
In a single-phase alternator one rotor pole is in the same position relative to a stator winding as any other rotor pole, all stator polar groups are cut by equal numbers of magnetic lines of force at any time as a result.
• A.

The ac voltages are in phase

• B.

Total induce voltage is 4 times the voltage induced in any one winding.

• C.

The voltage induced in any one winding have the same amplitude

• D.

All of the above

• 8.
The major difference between an alternator is the method of connection to the external circuit, that is the alternator is connected to the external circuit by______, but the DC generator is connected by a commutator.
• A.

Slip rings, brush

• B.

Slip rings,commutator

• C.

Commutator,slip rings

• D.

None of the above

• 9.
Unless  otherwise specified, any value given for  current or  voltage in an AC circuit is assumed to be:
• A.

Maximum

• B.

Instantaneous

• C.

Effective

• D.

Average

• 10.
High  voltage alternator is usually of the stationary armature rotating field type because:
• A.

It has commutator and brush

• B.

Slip ring have sort life

• C.

The slip ring have a hazard arc over

• D.

both b and c

• 11.
In delta connection
• A.

Phase voltage =line voltage

• B.

31/2 phase voltage = line voltage

• C.

Phase voltage =3 ½   line voltage

• D.

None of the above

• 12.
In a  wye connection, the total voltage or line voltage across any two phase is a vector sum of the individual phase voltages. For balance conditions the line voltage is _______ times the phase voltage.
• A.

1.414

• B.

1.73

• C.

0.707

• 13.
A transformer
• A.

Changes electrical energy into mechanical energy

• B.

changes electrical energy of a given voltage into electrical  energy  at a  different  voltage   level

• C.

Changes  mechanical  energy  into electrical  energy

• 14.
MTCS 1) a transformer can be used for pulsating DC 2) Transformer consist of two coils which are electrically connected
• A.

Only  1) is true

• B.

Only 2) is true

• C.

Both are true

• D.

None

• 15.
No transformer can be constructed 100% efficient because
• A.

Eddy current loss

• B.

Hysteresis

• C.

Leakage flux

• D.

All

• 16.
The measure of how well the flux of primary is coupled with the secondary is called
• A.

Coefficient of self inductance

• B.

Coefficient of coupling

• C.

Turns ratio

• D.

all

• 17.
The primary of a transformer develops 50,000 lines of force and only 45,000 lines cut acrose secondary ,the coefficient of coupling would be
• A.

50%

• B.

0.5

• C.

0.9

• D.

None

• 18.
A direct connected direct current generator is also called as ______ alternator.
• A.

Separately excited

• B.

Self excited

• C.

Brush less

• D.

None

• 19.
In __________ transformer the primary winding  and  secondary  windings are connected magnetically  as  well  as  electrically
• A.

Audio

• B.

Auto

• C.

Power

• D.

RF

• 20.
An  auto transformer  will  have
• A.

Less cost

• B.

Better regulations

• C.

Low loss as compare to ordinary two  windings transformers of the same rating

• D.

All of the above

• 21.
Unit of attenuation _________
• A.

Joule

• B.

Decibel

• C.

Watts

• 22.
Iron loss are also called as
• A.

Copper loss

• B.

Ohmic  loss

• C.

Core loss

• D.

All

• 23.
Copper loss is ______loss
• A.

I square Rt

• B.

Ohmic

• C.

Both a) and b)

• 24.
Efficiency of a transformer is given by
• A.

Output power /input power

• B.

Input power /output power

• C.

Out put magnetic lines of  force /input magnetic lines of force

• 25.
Which  filter  is used to pass  particular band of frequency?
• A.

Band pass

• B.

Band stop

• C.

Rejection filter

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