High Voltage Engineering Test Questions - Set 2

1)   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!


2)   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!


3)   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!


4)   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!


5)   Insulation is necessary for the protection of equipment. Insulation is not necessary between

a. Coils and earth
b. Coils of different phases
c. Turns in a coil
d. None of these
Answer  Explanation 

ANSWER: None of these

Explanation:
No explanation is available for this question!


6)   The temperature limit for class F insulation is

a. 105°C
b. 120°C
c. 130°C
d. 155°C
Answer  Explanation 

ANSWER: 155°C

Explanation:
No explanation is available for this question!


7)   Insulation of dry type transformers is done using prepregs. It is manufactured by using

a. Glass fibres
b. Nomex
c. Aramide papers
d. All of these
Answer  Explanation 

ANSWER: All of these

Explanation:
No explanation is available for this question!


8)   For insulators and bushings of power transformers, circuit breakers and instrument transformers, the suitable materials is

a. Epoxy resin
b. Polyesters resins
c. Porcelain
d. Silicon rubber
Answer  Explanation 

ANSWER: Porcelain

Explanation:
No explanation is available for this question!


9)   In the half wave rectifier, charging current can be limited by using an additional

a. Resistance in series with the secondary of the transformer
b. Inductance in series with the primary of the transformer
c. Inductance in series with the primary of the transformer
d. Capacitance in series with the secondary of the transformer
Answer  Explanation 

ANSWER: Resistance in series with the secondary of the transformer

Explanation:
No explanation is available for this question!


10)   The ripple voltage for half wave rectifier is

a. Smaller than that of full wave rectifier
b. Larger than that of full wave rectifier
c. Equal to that of full wave rectifier
d. None of these
Answer  Explanation 

ANSWER: Larger than that of full wave rectifier

Explanation:
No explanation is available for this question!