NEW
Font size
Worksheets3RD YEAR QUIZ BEE
Total questions: 45
Worksheet time: 1hrs 7mins
EASY
Which one of the following elements serves as a protection against overload?
Fuse
Switch
Resistor
Relay
A conducting part or a system of conducting parts through which an electric current flow or is intended to flow.
Ammeter
Current
Circuit
Components
What extends the range of a dc ammeter?
Inductance
Capacitor
Current transformer
Shunt resistance
If a capacitor is rated for 200V dc, what is its effective ac working voltage?
50 V
100 V
200 V
400 V
What is the reading of an ohmmeter for a shorted capacitor?
Zero
Infinity
k Ω
M Ω
In a series RLC circuit
The current lags VL by 90˚
The current leads VL by 90˚
XL leads Xc by 90˚
Z = jXL at resonance
Property of an electric circuit that dissipates electric energy
Reactance
Impedance
Resistance
Conductance
The impedance in the study of electronics is represented by resistance and
Inductance
Capacitance
Inductance and capacitance
Reactance
The graph between an alternating quantity and time is called
Sine wave
Curve
Waveform
A plot
Which of the following is the most popular waveform?
Sinusoidal
Square wave
Triangular
Sawtooth
What is the complex impedance of a circuit with an absolute resistance of 300 Ω?
0 + j 300 Ω
300 + j 90 Ω
0 – j 300 Ω
300 + j 0 Ω
The current is times the maximum current at half-power points of a resonance curve.
0.707
1.414
0.5
0.632
Kirchhoff’s laws (KCL and KVL) are applicable to
DC circuits
AC circuits
DC as well as AC circuits
Passive networks alone
What is considered as the most important value of a sine wave?
Effective value
Peak value
Average value
Instantaneous value
Which equation determines individual resistor voltage drop?
V x R
V x I
I x R
I² x R
For a DC generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher emf?
Lap winding
Wave winding
Either of (a) and (b) above
Depends on the design
Property of an electric circuit that dissipates electric energy
Reactance
Impedance
Resistance
Conductance
If a DC motor is to be selected for conveyors, which motor would be preferred?
Series motor
Differentially compound motor
Shunt motor
Cumulative compound motor
In an ac circuit with inductive reactance, the
Phase angle of the circuit is always 45˚
Voltage across the inductance must be 90˚ out-of-phase with the applied voltage
Current through the inductance lags its induced voltage by 90˚
Current through the inductance and voltage across it are180˚ out-of-phase
The capacity of a lead-acid cell is measured in
Amperes
ampere-hours
watts
watt-hours
AVERAGE
At what frequency will an inductor of 5mH have the same reactance as a capacitor of 0.1 μF?
7.12 kHz
7.12 Hz
7.12MHz
7.12 GHz
An ac series circuit is composed of a resistance of 20 Ω, inductive reactance of 40 Ω, and a capacitive reactance of 15 Ω. If a current of 1 ampere is flowing, what is the applied voltage?
320 V
32 V
220 V
22 V
Approximately how many milliamperes of current flow through a circuit with a 40 V source and 6.8 k of resistance?
27.2 mA
59 mA
5.9 mA
590 mA
A resistor and a capacitor are in series across a 20 V ac source. Circuit impedance is 4.33 k. Current flow in the circuit is
9.2 mA
92 mA
4.6 mA
460 mA
For a certain load, the true power is 150 W and the reactive power is 125 VAR. The apparent power is
19.52 W
195.2 W
275 W
25 W
A 2 kΩ resistor and a 0.002 F capacitor are in series across an ac source. Current in the circuit is 6.50 mA. The true power is
84.5 mW
845 mW
13 mW
130 mW
A 15 Ω resistor, an inductor with 8 Ω inductive reactance, and a capacitor with 12 Ω capacitive reactance are in parallel across an ac voltage source. The circuit impedance is
12.7 Ω
127 Ω
4,436 Ω
6,174 Ω
The total resistance of a parallel circuit is 50. If the total current is 120 mA, the current through the 270 resistor that makes up part of the parallel circuit is approximately
22 mA
120 mA
220 mA
50 mA
Five 100 resistors are connected in parallel. If one resistor is removed, the total resistance is
25 Ω
500 Ω
100 Ω
20 Ω
A load of 10 ohms was connected to a 12-volt battery. The current drawn was 1.18 amperes. What is the internal resistance of the battery?
0.10 Ω
0.17 Ω
0.25 Ω
0.30 Ω
A 10 ohms resistor is connected in parallel to the impedance of Z=3+j4. What is the power factor?
0.6
0.8
0.609
0.809
A 4-pole, 3-phase induction motor is energized from a 60-Hz supply and is running at a load condition for which the slip is 0.03. Determine speed of the rotor rotating magnetic field with respect to stator frame, in rpm.
1744 rpm
1764 rpm
1714 rpm
1800 rpm
In a parallel circuit, a resistance of 130 ohms and a capacitance of 30 microfarads are connected in parallel across a 230-volts, 50 Hertz supply. Find the angle difference between the total current and the applied voltage.
39.2o
52.8o
51.8o
50.8o
What is the total impedance of a 200 ohms resistance in parallel with a 200 ohms capacitive reactance?
100-j100 ohms
141.4-j141.4 ohms
200-j200 ohms
70.7-j70.7 ohms
Calculate the voltage induced in the armature winding of a 4-pole, wave-wound, dc machine having 728 active conductors and running at 1800rpm. The flux per pole is 30mWb.
1310.4 V
720.4 V
468.2 V
236.4 V
HARD
Given a sinusoidal voltage v = 200 cos (377t + 10ᵒ) volts; what is the magnitude of the voltage at t = 3.24 ms?
178.2 V
196.18 V
34.73 V
36.54 V
A coil has a 50 ohms resistance and a 70 ohms reactance. A capacitor is connected in parallel to produce resonance. The source voltage is 120 V. What is the power drawn by the circuit?
162 W
132 W
97 W
52 W
At what frequency, will the inductive reactance of a 0.0211-henry inductor be equal to the capacitive reactance of a 75-micro farad capacitor?
127 hz
185 hz
117 hz
90.7 hz
The resistance 100-ohm, inductance 50 mH and capacitance 50 Micro-farad are connected in series and across 240 volts source. What is the resonant frequency?
60 Hz
70 Hz
100Hz
1 Khz
The power factor of a load on a 120 volt, 60Hz source is raised from 0.707 to 0.866 lagging by connecting a 53 micro-farad capacitor across the load. What is the true power of the load in watts?
286 W
862 W
681 W
268 W
A circuit has impedance of 3.464+j2.0 ohm is supplied from a source voltage of 240 volts, 60 Hz. What is the current when resistance is reduced by 50%?
91 A
72 A
60A
54A
An induction motor has 8 poles, 60Hz, 3% slip. What is the rotor speed?
900 rpm
873 rpm
927 rpm
847 rpm
A 5-ohm resistance is connected in parallel with 10-ohm resistance. Another set, a 6-ohm and 8-ohm resistances are also connected in parallel. The two sets are connected in series. What is the equivalent resistance?
6.76 ohms
9.25 ohms
14.4 ohms
21.2 ohms
Two resistances of 10 and 15 ohms each respectively are connected in parallel. The two are then connected in series with a 5-ohm resistance. What is the equivalent resistance?
11 ohms
12 ohms
10 ohms
9 ohms
A series circuit consists of a 30-microfarad capacitance and a resistance of 50 ohms connected across a 110-volt, 60-hertz supply. Calculate the voltage drop across capacitor.
95.75V
55.56 V
93.3V
98.38 V
