Electrical Engineering · Question Bank

1P AC Circuits

136 of 161 questions match · page 2 of 7. Answer in your head first, then check the solution.

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TypeAll 136Problem solving 52Objective 84
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#21📜 EE Pre-Board August 2014📘 PowerhouseEasy
The current following in L and C at parallel resonance are
Azero
Bequal
Cinfinite
Ddifferent
#22📜 EE Pre-Board August 2014📘 PowerhouseEasy
At resonance, the impedance of a series RLC circuit is
Amaximum
Bminimum
Cinfinity
Dzero
#23📜 EE Pre-Board August 2014📘 PowerhouseEasy
At resonance, the current in a series RLC circuit is
Amaximum
Bminimum
Cinfinity
Dzero
#24📜 EE Pre-Board August 2014📘 PowerhouseEasy
In parallel RC circuit as the value of frequency increases the power factor _____.
ARemains the same
BBecomes unity
Cdecreases
Dincreases
#25📜 EE Pre-Board August 2014📘 PowerhouseEasy
The rms value of sinusoidal ac current is equal to its value at an angle of ______ degrees.
A45
B30
C90
D60
#26📜 EE Pre-Board August 2014📘 PowerhouseEasy
The current in a circuit is given by \(i = 50\sin\omega t\). If the frequency is 25 Hz, how long will it take for the current to rise to 25 A?
A0.02 sec
B\(3.33 \times 10^{-3}\) sec
C0.05 sec
D0.033 sec
#27📜 EE Pre-Board August 2014📘 PowerhouseEasy
An inductor supplied with 100V ac with a frequency of 10kHz passes a current of 10mA. The value of inductor is
A1.7 mH
B16 mH
C1 mH
D160 Mh
#28📜 EE Pre-Board March 2015📘 PowerhouseEasy
The net reactance in a series RLC circuit is
A\(X_L\)
B\(X_C\)
C\(X_C + X_L\)
D\(X_L - X_C\)
#29📜 EE Pre-Board March 2015📘 PowerhouseEasy
What is the power given \(v = 4\sin 3t\) and \(i = 4\sin 3t\)?
A\(16\sin(3t)^2\)
B\(16\sin^2(3t)\)
C\(8(1 - 6\cos 3t)\)
D\(16(1 - 6\cos 3t)\)
#30📜 EE Pre-Board March 2015📘 PowerhouseEasy
An inductance of 20 mH is connected in parallel with a capacitance of 80 μF. What is the frequency when \(X_L = X_C\)?
A100 HZ
B150 HZ
C128.5 HZ
D125.8 HZ
#31📜 EE Pre-Board March 2015📘 PowerhouseEasy
The apparent power supplied to a load in an ac circuit is 2,000 volt- amperes with a power factor of 0.6 lagging. The reactive power is most nearly:
A1,200 VAR
B3,333 VAR
C1,600 VAR
D2,500 VAR
#32📜 EE Pre-Board March 2015📘 PowerhouseEasy
Which wqave form will have the minimum rms value if they have the same peak value of voltage?
ASquare wave
BSine wave
CTriangular Wave
DFull wave rectified sine wave
#33📜 EE Pre-Board March 2015📘 PowerhouseEasy
A coil having a resistance of 3 Ω and an inductance of 0.01 H is connected in series with a capacitor across a voltage source of 220 volts. What must be the capacitance of the capacitor in order that maximum current occurs at 60 Hz?
A3.77 μF
B703.6 μF
C0.03 μF
D512.45 μF
#34📜 EE Pre-Board August 2015📘 PowerhouseEasy
Sparking occurs when a load is switched off because the circuit has high
ACapacitance
BInductance
CResistance
DImpedance
#35📜 EE Pre-Board August 2015📘 PowerhouseEasy
What is the ac current in a circuit if the impedance is (5 + j4) Ω and the voltage source, \(V_{rms}\), is 10 V?
A\(2.04\angle 38.7^\circ\) A
B\(1.56\angle -38.7^\circ\) A
C\(1.25\angle 54.3^\circ\) A
D\(1.11\angle -42.6^\circ\) A
#36📜 EE Pre-Board August 2015📘 PowerhouseEasy
If the capacitance in a series RLC ac circuit increases by a factor of 4, what happens to the resonant frequency?
AIt doubles
BIt stays the same
CIt decreases by 50%
DIt increases by 50%
#37📜 EE Pre-Board August 2015📘 PowerhouseEasy
In a series RL circuit, R = 20 Ω and L = 0.06 H. The current lags the voltage by 80°. Determine ω.
A1,890 rad/sec
B328 rad/sec
C1,980 rad/sec
D823 rad/sec
#38📜 EE Pre-Board August 2015📘 PowerhouseEasy
An alternating current is represented by \(i = 70.7\sin 520t\). Determine the value of the current 0.0015 second after passing through zero and increasing positively.
A49.7 A
B0.96 A
C24.8 A
D74.9 A
#39📜 EE Pre-Board August 2015📘 PowerhouseEasy
A complex current wave is represented by the equation \(i = 5 + 5\sin(120\pi t)\) A. Find its average value in amperes.
A4.5
B6
C5
D4
#40📜 EE Pre-Board August 2015📘 PowerhouseEasy
If resonant frequency is 10kHz and quality factor is 50, then
ABandwidth is 200 Hz
BXL=50,000 Ω
CR= 50 Ω
DXc= 50,000 Ω

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