⚡ Electrical Engineering Solved MCQs with Answers

Practice 757 approved ⚡ Electrical Engineering questions with verified answers from the 🛠️ Engineering Essentials subject for Pakistan exams.

757 solved MCQs

A 12 Ω resistor, a 40 μF capacitor, and an 8 mH coil are in series across an ac source. The resonant frequency isAnswer: 281 Hz The impedance at the resonant frequency of a series RLC circuit with L = 20 mH, C = 0.02 μF, and RW = 90 Ω isAnswer: 90 Ω Referring to Problem 20, what is the total parallel resistance (Rp(tot))?Answer: 4,992 Ω A 200 Ω resistor, a coil with 30 Ω of reactance, and a capacitor of unknown reactance are in series across an ac source. The circuit is at resonance. Circuit impedanceAnswer: is 200 Ω Referring to Problem 8, the total current isAnswer: 5.73 A If the resistance in parallel with a parallel resonant circuit is reduced, the bandwidthAnswer: decreases A resonant circuit has a lower critical frequency of 7 kHz and an upper critical frequency of 13 kHz. The bandwidth of the circuit isAnswer: 6 kHz If the value of C in a series RLC circuit is decreased, the resonant frequencyAnswer: increases To tune a parallel resonant circuit to a higher frequency, the capacitance should beAnswer: decreased A certain series resonant circuit has a bandwidth of 2 kHz. If the existing coil is replaced with one having a higher value of Q, the bandwidth willAnswer: decrease In a certain parallel resonant band-pass filter, the resonant frequency is 14 kHz. If the bandwidth is 4 kHz, the lower frequencyAnswer: is 12 kHz An RL low-pass filter consists of a 5.6 mH coil and a 3.3 kΩ resistor. The output voltage is taken across the resistor. The circuit's critical frequency isAnswer: 93.8 kHz In a series resonant band-pass filter, a lower value of Q results inAnswer: a larger bandwidth The maximum output voltage of a certain low-pass filter is 15 V. The output voltage at the critical frequency isAnswer: 10.60 V An RL high-pass filter consists of a 470 Ω resistor and a 600 mH coil. The output is taken across the coil. The circuit's critical frequency isAnswer: 125 Hz A series resonant band-pass filter consists of a 2 mH coil, a 0.005 μF capacitor, and a 120 Ω resistor. The winding resistance of the coil is 12 Ω. The output voltage is taken off the resistor. Input voltage is 12 Vrms. What is the output voltage magnitude at the center frequency (f0)?Answer: 10.9 V Referring to Problem 15, if the input voltage is a 6 V sine wave with a dc level of 10 V, what is the output voltage magnitude?Answer: 5.97 V In a certain low-pass filter, fc = 3.5 kHz. Its passband isAnswer: 0 Hz to 3.5 kHz A series resonant band-stop filter consists of a 68 Ω resistor, a 110 mH coil, and a 0.02 μF capacitor. The internal resistance, RW, of the coil is 4 Ω. Input voltage is 200 mV. Output voltage is taken across the coil and capacitor in series. What is the output voltage magnitude at f0?Answer: 11.1 mV A sinusoidal voltage with a peak-to-peak value of 18 V is applied to an RC low-pass filter. If the reactance at the input frequency is zero, the output voltage isAnswer: zero An RC high-pass filter consists of a 0.2 μF capacitor and a 220 Ω resistor. The output is taken across the resistor. The circuit's critical frequency isAnswer: 3,617 Hz When a 15 V input pulse with a width equal to two time constants is applied to an RC integrator, the capacitor charges toAnswer: 12.9 V An integrator consists of a 3.3 kΩ resistor and a 2 μF capacitor. A single 30 V, 6 ms pulse is applied to the input. How much will the capacitor charge?Answer: 17.91 V Referring to Problem 5, how long will it take the capacitor to discharge if the internal resistance of the pulse source is 100 Ω?Answer: 1.5 ms With an RL integrator, at the instant of the rising pulse edge,Answer: all the input voltage is across the inductor When a 12 V input pulse with a width equal to one time constant is applied to an RC integrator, the capacitor charges toAnswer: 7.56 V A steady-state condition is reached whenAnswer: the output voltage reaches the average value of the input voltage A single 6 V pulse with a width of 600 μs is applied to an integrator consisting of a 150 kΩ resistor and a 0.002 μF capacitor. To what voltage will the capacitor charge?Answer: 5.16 V To understand how the output voltage is shaped by a differentiator, you must considerAnswer: all of the above If the capacitor in an integrator becomes leaky,Answer: all of the above