1. As the transmission voltage
increases the volume of the conductor
a) Increases
b)
Decreases
c) Will not change
d) Will increase proportionately
Ans: (b)
2. The power transmission
capacity of the transmission line is
a) Proportional to the square
of the operating voltage
b)
Inversely proportional to the voltage
c)
Proportional to the voltage
d)
Inversely proportional to the square of the voltage
Ans: (a)
3. The overall capital cost of
the transmission decreases the voltage of transmission increases.
a) true
b)
false
Ans: (a)
4. Which of the following power
plant has the maximum efficiency?
a) Thermal power plant
b)
Hydro-electric power plant
c)
Atomic Reactor
d) MHD
Ans: (c)
5. The corona
loss in the transmission line can be reduced by increasing spacing between the
conductors or the diameter of the conductors.
a)
true
b)
false
Ans: (a)
6. The bundle conductors are
preferred for EHV transmission line because
a) It is easy to fabricate thin
conductors and combine them to make a bundle
b)
Overall inductance of the line is reduced and corona loss and radio
influences are minimum
c)
Height of the tower is reduced and hence cheap transmission
d)
Fabrication of the conductor is cheap
e)
Of erection difficulties
Ans: (b)
7. EHV d.c. transmission over
large distance is cheaper than EHV a.c. transmission
a) true
b)
false
Ans: (a)
8. The percentage reactance is
defined as
a) The
percentage of the ratio of change in reactance in transient condition to the
total reactance of the machine
b) The
percentage of the ratio of change in reactance in transient condition of the
total resistance of the machine
c) The
percentage of the ratio of voltage drop due to reactance synchronous machine to
the rated voltage when full load rating current is flowing
d) Either (a) and (c)
Ans: (c)
6. If the
secondary of the transformer having the reactance of 4% is short circuited with
normal voltage applied to the primary the symmetrical short circuit current
will be
a)
4 times of the full load current
b)
25 times of the full load current
c)
2 times of the full load current
d)
8 times of the full load current
e)
40 times of the full load current
Ans: (b)
10.
If the base kVA is 25,000 then a 5000 kVA alternator with 8% reactance
will have
a)
A 4% reactance
b)
A 40% reactance
c)
A 16% reactance
d)
A 20% reactance
Ans: (b)
11. The corona discharge on
transmission lines may be avoided by
a) Increasing effective
conductor radius
b)
Increasing the operating voltage
c)
Decreasing the spacing between the conductors
d)
None of these
Ans: (a)
12. Voltage gradient on a
transmission line conductor is highest
a)
At the surface of the conductor
b)
At the centre of the conductor
c)
At the distance equal to one radius from the surface
d) None of these
Ans: (a)
13.
Booster transformer is located at
a) Sending end of transmission line
b)
Intermediate point on a transmission
line
c)
Receiving end of transmission line
d)
None of these
Ans: (b)
14. The transmission line
between tower assumes the shape of a
a) Catanary
b)
Hyperbola
c)
Parabola
d)
Arc of a circle
Ans: (a)
15. Voltage control in a power
transmission line is achieved by
a) Booster transformer
b)
Tap-changing transformer
c) Injection of reactive power
d)
All of these
Ans: (d)
16. In a power transmission
line, the sag depends on
a) Conductor material alone
b)
Tension in conductors alone
c)
Span of transmission line
d) All of these Ans: (d)
17. For maximum
efficiency in transmission of bulk ac power, the power factor of the load
should be
a)
Unity
b)
Considerably less than unity
c)
Slightly less than unity leading
d)
Slightly less than unity lagging
Ans: (d)
18. Use of bundle conductors
causes the critical voltage for corona formation
a)
To decrease
b)
To increase
c)
To remain unlatered
d)
Does not existent
Ans: (b)
19. The function of guard ring
transmission lines is
a) To reduce the transmission losses
b)
To reduce the earth capacitance of the lowest unit
c)
To increase the earth capacitance of the lowest unit
d)
None of these
Ans: (a)
20. Series
acapacitors on transmission lines are of little use when the required reactive
voltamperes are
a) Small
b)
Large
c) Fluctuating
d) Any of these
Ans: (a)
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