T-20 Electrical MCQ

1➤ The ideal core should exhibit very High permeability in case of transformer and inductor core due to magnetic saturation caused by DC imbalance condition that can be minimise by

Low permeability core only Low and high permeability combination coreNo permeability coreHigh permeability core only

2➤ Which one of the following devices is not a switched mode DC power supply?

Resonant converter Full bridge converterPush full converters Fly back forward converters

3➤ In a closed loop control of squirrel cage induction motor the field oriented control strategy implemented in

Vector controlAdaptive control Scalar control Frequency control

4➤ For large power output multiphases rectifier are used along with filters to reduce level of harmonics by increasing the fundamental frequency in

Diode rectifier Star rectifierBridge rectifier Delta rectifier

5➤ In a photovoltaic system there is a thermally generated small reverse saturations current which flows even in the absense of light called

Photon currentLeakage currentDark current Diode current

6➤ In a HVDC transmission line the link which has to Circuit that are almost independent of each other is called

Bipolar linkMonopolar linkHomopolar linkDual polar link

7➤ Bundled conductor that are used to increase line voltage in EHV lines for raising critical corona voltage depend on

Number of conductors in the groupOptimum spacingVoltage gradientCommunication interface

8➤ Potier traingle method is helpful in obtaining the voltage regulation of synchrous machines by determining the armature

Leakage reactance and air gap flux Leakage reactance and its reaction mmfResistance and its reaction mmfResistance and air gap flux

9➤ The presence of ozone due to corona is harmful because it

Reduce power factorGives oudourCorrodes the materialTranfer energy to ground

10➤ An attenuator is a

R'S networkRC network RL network LC network

11➤ A buck converter is used to: -

Step down the voltageStep up the voltageStabilize the voltageExactly double the voltage

12➤ Total current or charge entering a junction is exactly equal to the charge leaving the node which means all the currents entering and leaving the junction should be equal to zero. Which circuit law is mentioned in this context?.

Conservation of ChargeBiot Savart LawConservation of EnergyAmpere's circuital law

13➤ Which among the following metals has maximum Curie temperature?

GadoliniumDysprosiumNickelIron

14➤ Soft iron is used in the manufacture of electromagnets because of its: -

High coercive field onlyHigh retentivity onlyHigh saturation magnetization, low retentivity and low coercive fieldLow saturation magnetization only

15➤ How many types of DC distributions systems are present solely based on the way they are fed by feeders?

3546

16➤ Which of the following network theorem is not applicable when only dependent source is present in circuit?.

Maximum power transfer theoremThevenin’s theoremNorton’s theoremSuperposition theorem

17➤ Which of the following is NOT a thyristor type?

SCRGTOUJTETO

18➤ The time base signal in a CRO is:

a triangular wave signala sawtooth signala sinusoidal signala square wave signal

19➤ The stall torque represents the point on the characteristics torque and speed graph of a dc motor at which the torque is a____ .

Minimum and the shaft is normal rotating speedMaximum, but the shaft is not rotating.Minimum, but the shaft is not rotatingMaximum and the shaft is normal rotating speed

20➤ In induction motor, the three phases of the stator are connected in series across either a single AC or DC source that type of connection braking is known as________.

DC Dynamic Braking AC Dynamic BrakingZero Sequence BrakingSelf-Excited Braking Using Capacitor

Your score is