Grading of Cables & Capacitance of Three core cables - MCQs with Answers
Grading of Cables & Capacitance of Three core cables - MCQs with AnswersQ1. What does capacitance grading of cables mean?
a. Use of dielectrics in different concentrations.
b. Introduction of capacitance at various lengths of cable to counter the effect of inductance.
c. Use of dielectrics of different permittivities.
d. Grading according to capacitance per km length of the cable.View Answer / Hide Answer
Q2. In a 3 core cable, the capacitance between two conductors is 3 μF. What will be the capacitance per phase?
ANSWER: c. Use of dielectrics of different permittivities.
a. 1.5 μ F
b. 3 μ F
c. 6 μ F
d. 12 μ FView Answer / Hide AnswerQ3. For the fig shown, what will be the capacitance between A and B
+ 3 Cc
) / 2
+ 2CSView Answer / Hide Answer
Q4. What is the source of heat generation in cables?
ANSWER: c. (CS + 3 Cc) / 2
a. Copper loss in conductor
b. Dielectric losses in cable insulation
c. Losses in metallic sheathings and armouring.
d. All of these.View Answer / Hide AnswerQ5. The capacitances of a 3 phase belted cable are 12.6 μ F between the three cores bunched together and the lead sheath and 7.4 μ F between one core and the other two connected to sheath. What will be the charging current drawn by the cable when connected to a 66 kV supply?
a. 100 A
b. 99.3648 A
c. 105.236 A
d. 107.74 AView Answer / Hide AnswerQ6. What is the safe working temperature for a conductor in case of armoured cables?
a. 50° C
b. 75° C
c. 65° C
d. 40° CView Answer / Hide AnswerQ7. Which tests are conducted to locate the fault location in the cables?
a. Murray loop test.
b. Varley loop test.
c. Both (a) and (b).
d. None of these.View Answer / Hide Answer
Q8. In a test by Murray loop for ground fault on 500 m of cable having a resistance of 1.6 Ω / km, the faulty cable is looped with the sound cable of some length and area of cross section. If the ratio of the other two arms of the testing network at balance is 3:1, what is the distance of fault from the testing end of cables?
ANSWER: c. Both (a) and (b).
a. 100 m
b. 200 m
c. 250 m
d. 300 mView Answer / Hide Answer
- RE: Grading of Cables & Capacitance of Three core cables - MCQs with Answers -ASHISH (08/21/16)
- explain Q.6