check

MCQ's Current Transformer Fundamentals

 If you think you have a good understanding of Current Transformer Fundamentals, challenge yourself and take the quiz.

Best of Luck.!!

Start

Question 1 of 20

Q.1 A current transformer is used to:

A

Step up current

B

Step down current

C

None of the above

Question 2 of 20

Q.2 The most common application of current transformer is: 

A

It is used for protection purpose

B

It is used for measuring purpose

C

Both

Question 3 of 20

Q.3 In CT, the current entering in the dot at the primary side of the winding:

A

Must exit from the dot at the secondary side

B

Must enter from the dot at the secondary side

C

None of the above

Question 4 of 20

Q.4 In a transformer, current is:

A

Directly proportional to number of turns

B

Inversely proportional to number of turns

C

None of the above

Question 5 of 20

Q.5 Considering primary current is kept constant, if it is required to have a lower current value at secondary side:

A

Number of turns at primary is increased

B

Number of turns at secondary is increased

C

Number of turns at primary is decreased

D

Both (a) & (b)

E

Both (b) & (c)

Question 6 of 20

Q.6 Calculate Primary current (Iₚ), when Iₛ = 2 Amp and Nₛ : Nₚ = 120 : 1.

A

120

B

240

C

60

Question 7 of 20

Q.7 The line current flowing to the ground in a Delta connected CT circuit is always:

A

Ila + Ilb + Ilc

B

Ila - Ilb - Ilc

C

Zero

D

-Ila - Ilb + Ilc

Question 8 of 20

Q.8 Keeping primary current and number of turns at primary constant if we double the number of turns at secondary, the secondary current becomes:

A

double

B

half

C

4 times

D

Remains same

Question 9 of 20

Q.9 In a current transformer, burden is:

A

Load connected at secondary side of transformer

B

Core impedance

C

Leakage impedance

Question 10 of 20

Q.10 During normal operation, a CT secondary can never be left:

A

Short

B

Open

C

None of the above

Question 11 of 20

Q.11 What is the relation of secondary voltage (Vs) and burden voltage (Vb) in a current transformer? 

A

Vs = Vb

B

Vs < Vb

C

Vs > Vb

Question 12 of 20

Q.12 The main requirement for a protection type CT is that it must have:

A

a high saturation point

B

a high accuracy class

C

a large turn ratio

Question 13 of 20

Q.13 The main requirement for a metering type CT is that it must have:

A

a high saturation point

B

a high accuracy

C

a large turn ratio

Question 14 of 20

Q.14 In additive polarity, primary and secondary have a phase shift of 

A

0°

B

180°

C

120°

Question 15 of 20

Q.15 In subtractive polarity, primary and secondary have a phase shift of 

A

0°

B

180°

C

120°

Question 16 of 20

Q.16 What will be the effect on CT, if its secondary terminal is ungrounded? 

A

Secondary end current increases

B

Secondary end voltage rises

C

No effects

Question 17 of 20

Q.17 Which of the following representation shows a protection class C.T:

A

0.2 S

B

5P20

C

0.1

Question 18 of 20

Q.18 Knee point voltage in C.T is defined as voltage beyond which:

A

10 % increase in secondary voltage will cause excitation current to increase by 50%

B

10 % increase in primary voltage will cause excitation current to increase by 50%

C

10 % increase in secondary voltage will cause secondary current to increase by 50%

Question 19 of 20

Q.19 In order to check the polarity of a CT, which test can be performed?

A

AC test

B

DC test

C

Current method

D

Phase angle method

E

All of the above

Question 20 of 20

Q.20 The magnetization impedance (Ze) is a ___________ quantity and is directly proportional to the ________________.

A

Linear, secondary current

B

Non-linear, secondary voltage

C

Linear, secondary voltage

D

Non-linear, secondary current

Confirm and Submit