Breakdown in solid dielectrics - Electrical Engineering (MCQ) questions and answers

1)   The example of artificial fibre is

a. Rayon
b. Cotton
c. Flax
d. Silk
Answer  Explanation 

ANSWER: Rayon

Explanation:
No explanation is available for this question!


2)   Which among the following is not an example of impregnants?

a. Mineral oil
b. Chlorinated diphenyl
c. Vegetable oils
d. None of these
Answer  Explanation 

ANSWER: None of these

Explanation:
No explanation is available for this question!


3)   For very small cavities, discharge inception voltage

a. Decreases as the cavity depth increases
b. Increases as the cavity depth increases
c. Remains unaffected as the cavity depth increases
d. None of these
Answer  Explanation 

ANSWER: Decreases as the cavity depth increases

Explanation:
No explanation is available for this question!


4)   The liquid dielectrics contain voids or cavities within the medium or at the boundaries between the dielectric and the electrodes. The electric field strength in the voids is

a. Lower than that across the dielectric
b. Higher than that across the dielectric
c. Equal to that across the dielectric
d. None of these
Answer  Explanation 

ANSWER: Higher than that across the dielectric

Explanation:
No explanation is available for this question!


5)   Treeing phenomenon is observed in

a. Capacitors
b. Cables
c. Insulators
d. Only (a) and (b)
Answer  Explanation 

ANSWER: Only (a) and (b)

Explanation:
No explanation is available for this question!


6)   The spreading of spark channels during tracking, in the form of the branches of a tree is called

a. Bunching
b. Treeing
c. sparking
d. none of these
Answer  Explanation 

ANSWER: Treeing

Explanation:
No explanation is available for this question!


7)   The thermal breakdown stresses are

a. Lower under ac conditions than under dc condition
b. Greater under ac condition than dc condition
c. Equal in both condition
d. None of these
Answer  Explanation 

ANSWER: Lower under ac conditions than under dc condition

Explanation:
No explanation is available for this question!


8)   Within dielectric, an electron starting from the cathode will drift towards the anode and during this motion

a. Gains energy from the field and loses during collision
b. Gains energy during both motion and collision
c. Loses energy during both motion and collision
d. Loses energy from the field and gains during collision
Answer  Explanation 

ANSWER: Gains energy from the field and loses during collision

Explanation:
No explanation is available for this question!


9)   Intrinsic breakdown occurs in time of the order of

a. 10-5 s
b. 105 s
c. 10-8 s
d. 108 s
Answer  Explanation 

ANSWER: 10-8 s

Explanation:
No explanation is available for this question!


10)   Which is having higher breakdown strength?

a. Solid dielectrics
b. Liquid dielectrics
c. Gases dielectrics
d. Equal in all
Answer  Explanation 

ANSWER: Solid dielectrics

Explanation:
No explanation is available for this question!