WorksheetsE_E_ 2023
Total questions: 17
Worksheet time: 6mins
Name
Class
Date
1.
A straight conductor 100cm long and carrying a current of 40A, lies perpendicular to a
magnetic field of 1.5 wb/m^2. What is the mechanical power in watt/s required to move the
conductor at a uniform speed of 5m/s?
a)
390 W
b)
330 W
c)
300 W
d)
360 W
2.
In an oscillating LC circuit, the total stores energy is U and the maximum charge on the
capacitor is Q. When the charge on the capacitor is Q/2, the energy stored in the inductor is:
a)
U/2
b)
U/4
c)
(4/3)U
d)
3U/4
3.
Which is not a source of noise in a communication system?
a)
Atmosphere
b)
Manufactured electrical equipment
c)
Another communication signal
d)
Thermal agitation in electronic component
4.
The unit of relative permeability is
a)
henry/metre
b)
henry
c)
henry/sq. m
d)
it is dimensionless
5.
A 345 KV transmission line has a series impedance (4 + j60) ohms and a shunt admittance of
j2 x10^-3S .Using 100 MVA and the line voltage as base values, calculate the per unit shunt
admittance of the line
a)
j3.57 p.u
b)
j4.76 p.u
c)
j2.38 p.u
d)
j5.56 p.u
6.
What is the relay that can detect overload in the line ?
a)
Fuses
b)
Magnetic Switch
c)
Differential Relay
d)
Overcurrent Relay
7.
Which of the following is not a consideration in surge arrester?
a)
arrester class
b)
current rating
c)
voltage rating
d)
insulation coordination
8.
A car battery has an open-circuit terminal voltage of 12.6 volts. The voltage drops to 10.8 volts
when the battery supplies 240 amps to the car's starter motor. What is the Thevenin equivalent
for this battery?
a)
0.0075
b)
0.0073
c)
0.0072
d)
0.0074
9.
If the torque angle d continuously increases, system will become
a)
stable
b)
unstable
c)
oscillatory stable
d)
asymptotic stable.
10.
Three sinusoidal generators and a battery are connected in series wih a coil whose resistance
and inductance are 8 Ω and 26.53 mH, respectively. The frequency and rms voltage of the
respective generators are 20 mH, 15 v, 60 hz, 30 v, and 80 Hz, 50 v. the battery voltage is 6 v.
determine the circuit rms voltage.
a)
10 v
b)
60.51 v
c)
101 v
d)
68.5 v
11.
A three-phase wye connected 20 MW load of pf 0.866 lagging is to be supplied by a
transmission line is 138 kV. It is desired that the line losses not exceed 5 percent of the load. If
the per phase resistance of the line is 0.7ohm, what is the maximumlength of the line?
a)
51km
b)
58km
c)
64km
d)
73km
12.
(Related Question Not Exact Wordings) In Power line Corridor, there shall be NO tall growing
plants such as vines and other plant species, which grow or have the potential to grow more than
_____ meters in height from the ground.
a)
2m
b)
3m
c)
1m
d)
6m
13.
Calculate the total resistance of 11- 33 kohms resistors connected in parallel
a)
1 kilo-ohms
b)
11 kilo-ohms
c)
363 kilo-ohms
d)
3 kilo-ohms
14.
A 120-V DC motor draws a current of 200 A and is located 1,000 feet from the supply. If the
copper transmission wire has a diameter or 0.45 Inch and with specific resistance of 10.4 ohm-
cmil per foot. What must be the voltage of the supply source?
a)
136.9
b)
129.1
c)
136.9
d)
140.5
15.
A 15-ohm resistor is connected in parallel with a series combination of resistors of 8 and 12
ohms. If the voltage drop across the 8-ohm resistor is 48 V, what is the total current in A?
TROUBLESHOOT: 15-ohms -> 12ohms, 12 ohms ---> 16 ohms
a)
16.0
b)
18.0
c)
22.0
d)
20.0
16.
An induction motor draws 50 kW at a 0.60 Tagging power factor from a 480 V, 60 Hz source.
What parallel capacitor will increase the overall power factor to 0.90 lagging?
a)
532 uF
b)
489 uF
c)
704 uF
d)
582 uF
17.
A 69 kV three-phase transposed line is composed of one ACSR 336,400 cmil,
26/7 Linnet conductor per phase with a horizontal configuration D = 5 ft, D = 5 ft, and D = 10 ft.
The conductors have a diameter of 0.721 inch and a GMR of 0.0243ft. Find the inductance per
phase per kilometer of the line.
a)
1.1116 mH/km
b)
1.1216 mH/km
c)
1.1136 mH/km
d)
1.1114 mH/km
100 %
