Power Quality And Management Set 3 MCQs

Q1 | The most common way to calculate voltage sag is from ______

Average Voltage

Peak Voltage

RMS Voltage

none of the above

Q2 | Effect of temperature rise in overhead lines is to

Increase Sag Decrease Tension

Decrease Sag Increase Tension

Increases both

Decreases Both

Q3 | What should be the value of sag for proper operation of overhead transmission line?

High

Low

Neither too low nor too high

Anything

Q4 | Voltage dips cannot be caused by which of the following:

Switching on of Large Loads

Local and Remote faults

Inductive Loading

Capacitive Switching

Q5 | Which one of the following cannot be possible with voltage surges:

Damaging to insulation

Tripping of Sensitive Equipment

Flicker in Incandescent Lamps

Damage to electronic components

Q6 | During sag, power electronic component will trip, this will decrease ______

Load Voltage

Supply Voltage

Load Current

none of the above

Q7 | The total power taken by the load remains constant so that _____ will be higher

Current

Voltage

Fluctuations

Harmonics

Q8 | The major cause of voltage sag is

Malfunction of primary component

Equipment Failure

Starting of large Induction Machine

All the above

Q9 | To obtain a constant current input, a inductor is placed in current source inductor(CSI) in:

Parallel

Series

Both Series and Parallel

Not placed at all

Q10 | The harmonic current distortion in adjustable speed drive is_____

Constant

Not Constant

High

low

Q11 | Reducing the number of short-circuit faults in a system, reduces ______

Sag

Interruptions

Sag & Interruptions

none of the above

Q12 | Current-limiting fuses are able to clear a fault within one _______.

Half cycle

full cycle

will not clear

none of the above

Q13 | By implementing changes in the supply system, the severity of the event will__.

Reduce

Increase

Remains the same

None of the above

Q14 | The main mitigation equipments is___

UPS

Storage device

voltage source converter

All the above

Q15 | During normal operation, the UPS takes its power from the supply, rectifies the acvoltage to dc and inverts it again to ac with the

same frequency and rms value

Different frequency and rms value

same frequency and different rms value

Different frequency and same rms value

Q16 | What is the value of transient stability limit?

Higher than steady state stability limit

Lower than steady state stability limit.

Depending upon the severity of load

All of these

Q17 | By using which component can the transient stability limit of a power system be improved?

Series resistance

Series capacitor

Series inductor

Shunt resistance

Q18 | What is transient stability limit?

The maximum flow of power through a particular point in the power system without loss of stability when small disturbances occur.

The maximum power flow possible through a particular component connected in the power system.

The maximum flow of power through a particular point in the power system without loss of stability when large and sudden disturbances occur

All of these

Q19 | Which among the following methods is used for improving the system stability?

Increasing the system voltage

Reducing the transfer reactance

Using high speed circuit breaker

All of these

Q20 | What is steady state stability limit?

The maximum flow of power through a particular point in the power system without loss of stability when small disturbances occur.

The maximum power flow possible through a particular component connected in the power system.

The maximum flow of power through a particular point in the power system without loss of stability when sudden disturbances occur

All of these

Q21 | Which among these is a classification of power system stability?

Frequency stability

Voltage stability

Rotor angle stability

All of these

Q22 | The stability of the power system is not affected by which among these?

Generator reactance

Line losses

Excitation of generators

All of these

Q23 | What is power system stability?

The maximum power flow possible through a particular component connected in the power system.

The ability of the power system to regain the state of operating equilibrium point when the system is subjected to any disturbances.

It is a phenomenon in which a power system losses its operating equilibrium when subjected to large disturbances.

All of these

Q24 | Power factor can be mathematically expressed as:

P/Q

Q/P

P/S

S/P

Q25 | The power factor angle of a purely inductive circuit is:

45 degree

60 degree

75 degrees

90 degree