Download PDF
Free download in PDF High Voltage Engineering Objective Type Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
(21)
Which among the following is not an example of impregnants?
[A]
Mineral oil
[B]
Chlorinated diphenyl
[C]
Vegetable oils
[D]
None of these
(22)
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: Decreases as the cavity depth increases
(23)
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: Higher than that across the dielectric
(24)
Treeing phenomenon is observed in
[A]
Capacitors
[B]
Cables
[C]
Insulators
[D]
Only (a) and (b)
(25)
According to the Stressed Oil Volume theory, the breakdown strength is
[A]
Directly proportional to the stressed oil volume
[B]
Directly proportional to the square of the stressed oil volume
[C]
Inversely proportional to the stressed oil volume
[D]
None of these
Answer: Inversely proportional to the stressed oil volume
(26)
According to the Bubble theory, once a bubble is formed, it will elongate in the direction of electric field under the influence of electrostatic forces. During elongation the volume of bubbles
[A]
Increases
[B]
Decreases
[C]
Remains constant
[D]
None of these
(27)
In case of solid particles present in the liquid and in case of presence of only gas bubbles in liquids, the direction of force is towards
[A]
Areas of maximum stress, areas of minimum stress
[B]
Areas of maximum stress, areas of maximum stress
[C]
Areas of minimum stress, areas of maximum stress
[D]
Areas of minimum stress, areas of minimum stress
Answer: Areas of maximum stress, areas of minimum stress
(28)
The increase in liquid hydrostatic pressure
[A]
Increases the breakdown strength
[B]
Decreases the breakdown strength
[C]
Does not affect the breakdown strength
[D]
None of these
Answer: Increases the breakdown strength
(29)
In Breakdown tests, the tests voltages required for these tests are usually of the order of
[A]
0 – 10 kV
[B]
20 – 50 kV
[C]
50 – 100 kV
[D]
100 – 200 kV
(30)
Field in case of rod gaps and sphere gaps are
[A]
Uniform, uniform
[B]
Uniform, non-uniform
[C]
Non-uniform, uniform
[D]
Non-uniform, non-uniform
Answer: Non-uniform, uniform
31
For the high voltage conductors at high pressures, if the voltage is positive then the corona appears as a
[A]
Uniform bluish white sheath
[B]
Reddish glowing spots
[C]
Uniform greenish spots
[D]
None of these
Answer: Uniform bluish white sheath
32
According to the Paschen’s Law, the breakdown voltage of a uniform field gap is
[A]
Directly proportional to the gas pressure and inversely proportional to the electrode gap
[B]
Inversely proportional to the gas pressure and directly proportional to the electrode gap
[C]
Directly proportional to the both electrode gap and gas pressure
[D]
Inversely proportional to the both electrode gap and gas pressure
Answer: Directly proportional to the both electrode gap and gas pressure
33
The statistical time lag depends upon the
[A]
Size of gap
[B]
Quantity of radiation that produces the primary electrons
[C]
Amount of pre-ionization preset gap
[D]
All of these
34
Formative time lag depends on the mechanism of the avalanche growth in gap. The formative time lag is usually
[A]
Much shorter than the statistical time lag
[B]
Much greater than the statistical time lag
[C]
Equal to the statistical time lag
[D]
None of these
Answer: Much shorter than the statistical time lag
35
In routine tests, the cable is tested by applying an ac voltage of
[A]
2 times the rated value
[B]
2.5 times the rated value
[C]
3 times the rated value
[D]
3.5 times the rated value
Answer: 2.5 times the rated value
36
At the instant of contact separation in asymmetrical tests, the dc component is
[A]
Equal to the ac component
[B]
Equal to the 50% of ac component
[C]
Greater than 50% of the ac component
[D]
Less than the 50% of the ac component
Answer: Greater than 50% of the ac component
37
While performing temperature rise tests, at any part of the bushing the steady temperature rise above the ambient air temperature should not exceed
[A]
20 °C
[B]
25 °C
[C]
35 °C
[D]
45 °C
38
The tests which is not performed under power frequency tests is
[A]
Partial discharge tests
[B]
Momentary withstand test
[C]
Visible discharge tests
[D]
Full wave withstand tests
Answer: Full wave withstand tests
39
The voltage which produces the loss of dielectric strength of insulation is known as
[A]
Withstand voltage
[B]
Disruptive discharge voltage
[C]
Flashover voltage
[D]
Impulse voltage
Answer: Disruptive discharge voltage
40
Series capacitance voltmeters were used with cascade transformers for measuring rms values up to
[A]
100 kV
[B]
500 kV
[C]
800 kV
[D]
1000 kV
Take Mock Tests