Important MCQ on Power systems - 9
1.
When a pumped storage power plant is operated in
conjunction with a steam power plant
a.
The operating cost of the steam plant becomes
optimum
b.
Load factor of the steam
plant is increased
c.
Chances of the tripping of the system decreases
because of the use of two heterogeneous types of plants
d.
Operation of the storage plant in the pumping
mode during the low-load period improves the steam-plant stability
2.
Usage of materials in components of a nuclear
reactor:
Graphite is used in
moderators; Boron is used in control
rods ; Sodium is used as a
coolant ; Concrete is used as a
shield
3.
A 100km long transmission line is loaded at
110kV. If the loss of line is 15MW and the load is 150MVA, the resistance of
the line is
a.
8.06 ohms per phase
b.
0.806 ohms per phase
c.
0.0806 ohm per phase
d.
80.6 ohms per phase
4.
Two insulator discs of identical capacitance
value C make up string for a 22kV, 50Hz, single-phase overhead line insulation
system. If the pin to earth capacitance is also C, then the string efficiency
is
a.
50%
b.
75%
c.
90%
d.
86%
5.
Which one of the following statements is NOT
correct for the use of bundled conductors in transmission lines?
a.
Control of voltage gradient
b.
Reduction in corona loss
c.
Reduction in radio interference
d.
Increase in interference
with communication lines
6.
A power system consists of two areas connected
via a tie line. While entering the data for load flow the tie line parameters
and its connectivity data were inadvertently left out. If the load flow program
is run with this incomplete data, then the load flow calculations will converge
only if
a.
One slack bus is specified in the first area
b.
One slack bus is specified in the second area
c.
One slack bus is specified in either of the two
areas
d.
Two slack buses, one in
each area are specified
7.
The zero sequence current of a generator for
line to ground fault is j2.4 p.u. then the current through the neutral during
the fault is
a.
j2.4 p.u
b.
j 0.8 p.u
c.
j 7.2 p.u
d.
j 0.24 p.u
8.
in HVDC transmission there are predominant
a.
Voltage harmonics on DC
side and current harmonics on AC side of converters
b.
Current harmonics on DC side and voltage
harmonics on AC side of converters
c.
Current harmonics only on the DC side of
Converters
d.
Voltage harmonics only on the AC side of
converters
9.
Which one of the following statements is
correct? Corona loss increase with
a.
Decrease in conductor size and increase in
supply frequency
b.
Increase in both
conductor size and supply frequency
c.
Decrease in both conductor size and supply
frequency
d.
Increase in conductor size & decrease in
supply frequency
10.
For affixed receiving end and sending end
voltage in a transmission system, what is the locus of the constant power?
a.
A straight line
b.
An ellipse
c.
A parabola
Comments