Power Quality and Management (2180911) MCQs

MCQs of Power Frequency Disturbance

Showing 11 to 20 out of 21 Questions
11.
As the voltage source becomes larger (lower source impedance), the tendency to produce voltage flicker due to the operation of arc furnaces is ________
(a) increased
(b) reduced
(c) remains unchanged
(d) insufficient data
Answer:

Option (b)

12.
The noise frequency generated by the ASDs is typically ___________ the harmonic frequencies of the fundamental voltage
(a) higher than
(b) lower than
(c) same as
(d) half of
Answer:

Option (a)

13.
As the low-frequency disturbances are easily detected or measured, but, they are not easily corrected.
(a) True
(b) False
Answer:

Option (a)

14.
Choose the correct option. (i) Isolation transformers do not help in curing voltage sags (ii) Isolation transformers helps in curing voltage swells (iii) isolation transformers help to minimize noise coupling
(a) Only (i) & (ii)
(b) Only (i) & (iii)
(c) Only (ii) & (iii)
(d) (i), (ii) & (iii)
Answer:

Option (b)

15.
______________ devices that can maintain a constant voltage (within tolerance) for voltage changes of predetermined limits above and below the nominal value
(a) Voltage regulators
(b) Lightning arresters
(c) Isolation transformers
(d) Shielded transformers
Answer:

Option (a)

16.
Typically, ________________ transformer is used as voltage regulator.
(a) Isolation
(b) Shielded
(c) Ferro-resonance
(d) Distribution
Answer:

Option (c)

17.
The full form of UPS is
(a) Unidirectional Power Supply
(b) Uninterruptible Power Supply
(c) Undefined Power Supply
(d) Unified Power Supply
Answer:

Option (b)

18.
In ____________ UPS units, normal power is rectified into DC power and in turn inverted to AC power to supply the loads
(a) online
(b) offline
Answer:

Option (a)

19.
In the ___________ units, the loads are normally supplied from the primary electrical source directly.
(a) offline
(b) online
Answer:

Option (a)

20.
The output voltage of static UPS units tends to contain waveform distortions __________ those for normal power derived from the utility or a generator
(a) less than
(b) higher than
(c) Same as
Answer:

Option (b)

Showing 11 to 20 out of 21 Questions