30 + Interview Questions in Introduction To Alternating Currents And Voltages in Network Theory Page 1 InterviewSolution

1.	One sine wave has a positive peak at 75⁰, and another has a positive peak at 100⁰. What is the phase angle between two sine waves?(a) 10⁰(b) 15⁰(c) 20⁰(d) 25⁰The question was asked in an internship interview.My question is based upon Phase Relation in a Pure Resistor topic in division Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct answer is (d) 25⁰ The BEST I can explain: As first sine WAVE has a positive peak at 75⁰, and ANOTHER has a positive peak at 100⁰. The phase ANGLE between TWO sine waves mentioned above is 25⁰.

Discussion

2.	One sine wave has a positive peak at 75⁰, and another has a positive peak at 100⁰. How much is second sine wave shifted in phase from the 0⁰ reference?(a) lags reference angle by 15⁰(b) leads reference angle by 15⁰(c) lags reference angle by 10⁰(d) leads reference angle by 10⁰This question was posed to me in examination.This key question is from Phase Relation in a Pure Resistor topic in division Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct option is (a) LAGS REFERENCE angle by 15⁰ Explanation: As FIRST sine WAVE has a positive peak at 75⁰, and another has a positive peak at 100⁰. SECOND sine wave lags reference angle by 15⁰ from the 0⁰ reference.

Discussion

3.	One sine wave has a positive peak at 75⁰, and another has a positive peak at 100⁰. How much is first sine wave shifted in phase from the 0⁰ reference?(a) leads reference angle by 10⁰(b) lags reference angle by 10⁰(c) leads reference angle by 15⁰(d) lags reference angle by 15⁰This question was addressed to me in exam.My doubt stems from Phase Relation in a Pure Resistor topic in chapter Introduction to Alternating Currents and Voltages of Network Theory
Answer» Correct choice is (c) LEADS reference ANGLE by 15⁰ Easy EXPLANATION: As first SINE WAVE has a positive peak at 75⁰, and another has a positive peak at 100⁰. First sine wave leads reference angle by 15⁰ from the 0⁰ reference.

Discussion

4.	The impedance value of a pure capacitor is?(a) ωC(b) 1/ ωC(c) ωL(d) RThis question was posed to me in a national level competition.This interesting question is from Phase Relation in a Pure Resistor in section Introduction to Alternating Currents and Voltages of Network Theory
Answer» The CORRECT CHOICE is (b) 1/ ωC For explanation: The IMPEDANCE value of a pure capacitor is 1/ ωC. And the impedance of the capacitor is called CAPACITIVE reactance.

Discussion

5.	In case of pure capacitor, the voltage?(a) leads the voltage by 90⁰(b) lags behind the voltage by 45⁰(c) lags behind the voltage by 90⁰(d) is in phase with the voltageI have been asked this question in an interview for internship.My enquiry is from Phase Relation in a Pure Resistor topic in section Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct choice is (c) lags behind the VOLTAGE by 90⁰ Best EXPLANATION: In a capacitor, there exists a phase DIFFERENCE between current and voltage. In CASE of pure capacitor, the voltage lags behind the voltage by 90⁰.

Discussion

6.	The current in the pure capacitor?(a) lags behind the voltage by 90⁰(b) is in phase with the voltage(c) lags behind the voltage by 45⁰(d) leads the voltage by 90⁰The question was posed to me in an interview for job.This interesting question is from Phase Relation in a Pure Resistor topic in portion Introduction to Alternating Currents and Voltages of Network Theory
Answer» CORRECT answer is (d) leads the VOLTAGE by 90⁰ Best explanation: In a capacitor, there exists a phase DIFFERENCE between current and voltage. The current in PURE capacitor leads the voltage by 90⁰.

Discussion

7.	The value of inductance reactance is?(a) R(b) ωL(c) 1/ωL(d) ωCThis question was addressed to me during an online interview.Enquiry is from Phase Relation in a Pure Resistor topic in section Introduction to Alternating Currents and Voltages of Network Theory
Answer» RIGHT option is (b) ωL The explanation is: The VALUE of inductance reactance is ωL. Hence a pure INDUCTOR has an IMPEDANCE WHOSE value is ωL.

Discussion

8.	For inductor, what is the current?(a) is out of phase with the current(b) leads the current by 90⁰(c) is in phase with the current(d) lags behind the current by 90⁰The question was posed to me in final exam.The above asked question is from Phase Relation in a Pure Resistor topic in section Introduction to Alternating Currents and Voltages of Network Theory
Answer» The CORRECT OPTION is (d) LAGS BEHIND the current by 90⁰ The best I can explain: For inductor, the voltage and current are out of PHASE. So, the current lags behind the current by 90⁰.

Discussion

9.	In the case of inductor, the voltage?(a) is in phase with the current(b) lags behind the current by 90⁰(c) leads the current by 90⁰(d) is out of phase with the currentThis question was addressed to me during an online exam.This intriguing question comes from Phase Relation in a Pure Resistor in portion Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct option is (c) leads the CURRENT by 90⁰ The EXPLANATION: In the case of INDUCTOR, the VOLTAGE and current are out of phase. So, the voltage leads the current by 90⁰.

Discussion

10.	The phase difference between voltage and current in case of resistor is?(a) in phase(b) out of phase(c) 45⁰ out of phase(d) 90⁰ out of phaseThis question was addressed to me in an international level competition.My doubt is from Phase Relation in a Pure Resistor in chapter Introduction to Alternating Currents and Voltages of Network Theory
Answer» Right answer is (a) in phase To explain I would say: The phase difference between voltage and current in case of RESISTOR is in phase. The amplitudes of the waveform MAY DIFFER according to the value of RESISTANCE.

Discussion

11.	The form factor of the sinusoidal waveform is?(a) 1.11(b) 2.22(c) 3.33(d) 4.44I got this question during an interview for a job.My query is from Voltage and Current Values of a Sine Wave topic in section Introduction to Alternating Currents and Voltages of Network Theory
Answer» Correct choice is (a) 1.11 The explanation is: Form factor of any waveform is defined as the RATIO of the RMS VALUE to the AVERAGE value of the wave. Form factor = Vrms/Vav = (Vp/√2)/0.637Vp=1.11.

Discussion

12.	A wire is carrying a direct current of 20A and a sinusoidal alternating current of peak value 20A. Find the rms value of the resultant current.(a) 24(b) 24.5(c) 25(d) 25.5The question was posed to me during an interview.My doubt is from Voltage and Current Values of a Sine Wave in portion Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct ANSWER is (b) 24.5 To elaborate: DIRECT CURRENT = 20A, sinusoidal alternating current of PEAK value = 20A. The RMS value of the combined wave = √(20^2+20^2/2) = 24.5A.

Discussion

13.	The peak factor of the sinusoidal waveform is?(a) 4(b) 2(c) 1.414(d) 8This question was posed to me in an international level competition.My enquiry is from Voltage and Current Values of a Sine Wave topic in division Introduction to Alternating Currents and Voltages of Network Theory
Answer» CORRECT option is (c) 1.414 The best explanation: The peak FACTOR of any waveform is defined as the RATIO of the peak value of the WAVE to the rms value of the wave. Peak factor = Vp/(VRMS) = Vp/(Vp/√2)=√2=1.414.

Discussion

14.	The RMS value of sine wave is?(a) 0.707Vp(b) 0.607Vp(c) 0.807Vp(d) 0.907VpThis question was posed to me during an online exam.My doubt is from Voltage and Current Values of a Sine Wave topic in section Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct answer is (a) 0.707Vp The BEST I can EXPLAIN: The root mean SQUARE value of a sine wave is a measure of the HEATING effect of the wave. The RMS value of sine wave is 0.707Vp.

Discussion

15.	The value from positive to negative peak of the sine wave is called?(a) effective value(b) average value(c) peak value(d) peak to peak valueThe question was asked by my school teacher while I was bunking the class.This interesting question is from Voltage and Current Values of a Sine Wave topic in division Introduction to Alternating Currents and Voltages of Network Theory
Answer» Right answer is (d) peak to peak VALUE To explain: The value from POSITIVE to negative peak of the sine wave is CALLED peak to peak value of a sine wave.

Discussion

16.	The total area under the complete curve divided by the distance of the curve is called?(a) peak to peak value(b) RMS value(c) average value(d) effective valueThe question was asked by my school principal while I was bunking the class.This question is from Voltage and Current Values of a Sine Wave in section Introduction to Alternating Currents and Voltages of Network Theory
Answer» Correct option is (c) average value To elaborate: The TOTAL area under the complete curve divided by the DISTANCE of the curve is CALLED average value. The average value of a sine WAVE over on e complete cycle is always zero.

Discussion

17.	The maximum value of the wave during a positive half cycle or maximum value of the wave during negative cycle is called?(a) instantaneous value(b) peak value(c) peak to peak value(d) average valueI have been asked this question during an internship interview.I'm obligated to ask this question of Voltage and Current Values of a Sine Wave in chapter Introduction to Alternating Currents and Voltages of Network Theory
Answer» Correct answer is (b) peak VALUE To elaborate: The maximum value of the wave during positive half cycle or maximum value of the wave during NEGATIVE cycle is called peak value. Since the values of these TWO are equal in magnitude, a SINE wave is characterized by a single peak value.

Discussion

18.	The value of the sine wave at some particular instant is called?(a) peak value(b) peak to peak value(c) instantaneous value(d) average valueThe question was asked in unit test.This is a very interesting question from Voltage and Current Values of a Sine Wave topic in portion Introduction to Alternating Currents and Voltages of Network Theory
Answer» Right CHOICE is (C) INSTANTANEOUS value To EXPLAIN: The value of the sine wave at some particular instant is called instantaneous value. This value is different at different points ALONG the waveform.

Discussion

19.	Find the instantaneous value at 90⁰ point of the sine wave if the wave is shifted by 45⁰.(a) 5.66(b) 6.66(c) 7.66(d) 8.66The question was asked during an internship interview.My question is from Voltage and Current Values of a Sine Wave topic in section Introduction to Alternating Currents and Voltages of Network Theory
Answer» The CORRECT answer is (a) 5.66 The best I can explain: The EQUATION for sine WAVE A is v(t) = 10sinωt. The equation for sine wave A is v(t) = 8SIN(ωt-π/4). ωt= π/2. v (t) = 8sin(π/2-π/4) = 8sin45⁰=8(0.707) = 5.66V.

Discussion

20.	Find the instantaneous value of the sine value at 90⁰ point having an amplitude 10V and time period 360⁰.(a) 5(b) 10(c) 15(d) 20The question was asked during an online interview.The question is from Voltage and Current Values of a Sine Wave in portion Introduction to Alternating Currents and Voltages of Network Theory
Answer» Right choice is (b) 10 The best explanation: The EQUATION for SINE WAVE A is v(t) = 10sinωt. The VALUE at 90⁰ in this wave is v (t) = 10sin90⁰ = 10V.

Discussion

21.	A sine wave completes full cycle in ____ radians.(a) π(b) 2π(c) π/4(d) π/2I had been asked this question in examination.Question is from Angular Relation of a Sine Wave topic in section Introduction to Alternating Currents and Voltages of Network Theory
Answer» The CORRECT CHOICE is (b) 2π For explanation I would say: The PERIOD of a SINE wave is 360⁰ or 2π radians. So, a sine wave takes 90⁰ or 2π radians to complete a full CYCLE.

Discussion

22.	A sine wave completes quarter cycle in ____ radians.(a) 2π(b) π(c) π/2(d) π/4The question was asked at a job interview.The origin of the question is Angular Relation of a Sine Wave in portion Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct choice is (d) π/4 To explain: The period of a sine wave is 360⁰ or 2π radians. So, a sine wave TAKES 45⁰ or π/4 radians to COMPLETE a QUARTER CYCLE.

Discussion

23.	A sine wave completes half cycle in ____ radians.(a) π/2(b) π(c) π/4(d) 2πI got this question in an interview.My question is taken from Angular Relation of a Sine Wave in chapter Introduction to Alternating Currents and Voltages of Network Theory
Answer» Right ANSWER is (b) π The EXPLANATION is: The period of a sine WAVE is 360⁰ or 2π radians. So, a sine wave takes 90⁰ or π/2 radians to complete a HALF CYCLE.

Discussion

24.	The frequency of a sine wave is 30Hz. What is its period?(a) 3333ms(b) 333.3ms(c) 33.33ms(d) 3.333msThe question was posed to me by my school principal while I was bunking the class.This is a very interesting question from Angular Relation of a Sine Wave topic in chapter Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct CHOICE is (C) 33.33ms The best explanation: We KNOW that the frequency and time PERIOD are inversely proportional to each other. SoT=1/f =1/30=0.03333s=33.33ms.

Discussion

25.	The period of a sine wave is 40ms. What is the frequency?(a) 25(b) 50(c) 75(d) 100This question was posed to me in an online interview.This intriguing question originated from Angular Relation of a Sine Wave in chapter Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct option is (a) 25 The explanation is: We know that the frequency and time PERIOD are INVERSELY PROPORTIONAL to each other. So f = 1/T = 1/40ms = 25HZ.

Discussion

26.	The relation between frequency and time period is?(a) f=1/T(b) f=T(c) f=1/T^2(d) f=1/T^3This question was posed to me in an internship interview.Origin of the question is Angular Relation of a Sine Wave in division Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct answer is (a) f=1/T Explanation: The relation between FREQUENCY and TIME PERIOD is f=1/T. So the frequency and time period are INVERSELY PROPORTIONAL to each other.

Discussion

27.	The number of cycles a wave completes in one second is called?(a) time period(b) frequency(c) energy(d) wavelengthI had been asked this question in an interview for job.I'm obligated to ask this question of Angular Relation of a Sine Wave in chapter Introduction to Alternating Currents and Voltages of Network Theory
Answer» Correct answer is (b) FREQUENCY The explanation is: The NUMBER of cycles a wave completes in ONE second is called frequency. And the TIME period is the inverse of frequency.

Discussion

28.	The period of a function is measured as?(a) zero crossing of one cycle to zero crossing of next cycle(b) positive peak of one cycle to positive peak of next cycle(c) negative peak of one cycle to negative peak of next cycle(d) all of the mentionedThe question was posed to me during an internship interview.This is a very interesting question from Angular Relation of a Sine Wave in section Introduction to Alternating Currents and Voltages of Network Theory
Answer» CORRECT ANSWER is (d) all of the mentioned Easiest explanation: The PERIOD of a function is measured as ZERO crossing of one cycle to zero crossing of NEXT cycle or positive peak of one cycle to positive peak of next cycle or negative peak of one cycle to negative peak of next cycle.

Discussion

29.	If a function f(t) is periodic, then?(a) f(t) = f(t+T)(b) f(t) = f(t+T/2)(c) f(t) = f(t+T/4)(d) f(t) = f(t+T/8)I had been asked this question in homework.I need to ask this question from Angular Relation of a Sine Wave topic in portion Introduction to Alternating Currents and Voltages of Network Theory
Answer» The correct ANSWER is (a) F(t) = f(t+T) EASY explanation: If a function f(t) is periodic, then f(t) = f(t+T) in general we can SAY that a function f(t) is periodic, then f(t) = f(t+nT) for all integer values of N.

Discussion

30.	The response of a second order system is?(a) pulse(b) saw tooth(c) square(d) sinusoidThe question was posed to me in an internship interview.I want to ask this question from Angular Relation of a Sine Wave topic in portion Introduction to Alternating Currents and Voltages of Network Theory
Answer» Correct choice is (d) SINUSOID To elaborate: The response of a second order SYSTEM is sinusoid. Any periodic WAVEFORM can be written in terms of sinusoidal function according to FOURIER transform.

Discussion

Explore topic-wise InterviewSolutions in .

The impedance value of a pure capacitor is?(a) ωC(b) 1/ ωC(c) ωL(d) RThis question was posed to me in a national level competition.This interesting question is from Phase Relation in a Pure Resistor in section Introduction to Alternating Currents and Voltages of Network Theory

The value of inductance reactance is?(a) R(b) ωL(c) 1/ωL(d) ωCThis question was addressed to me during an online interview.Enquiry is from Phase Relation in a Pure Resistor topic in section Introduction to Alternating Currents and Voltages of Network Theory

The form factor of the sinusoidal waveform is?(a) 1.11(b) 2.22(c) 3.33(d) 4.44I got this question during an interview for a job.My query is from Voltage and Current Values of a Sine Wave topic in section Introduction to Alternating Currents and Voltages of Network Theory

The peak factor of the sinusoidal waveform is?(a) 4(b) 2(c) 1.414(d) 8This question was posed to me in an international level competition.My enquiry is from Voltage and Current Values of a Sine Wave topic in division Introduction to Alternating Currents and Voltages of Network Theory

The RMS value of sine wave is?(a) 0.707Vp(b) 0.607Vp(c) 0.807Vp(d) 0.907VpThis question was posed to me during an online exam.My doubt is from Voltage and Current Values of a Sine Wave topic in section Introduction to Alternating Currents and Voltages of Network Theory

A sine wave completes full cycle in ____ radians.(a) π(b) 2π(c) π/4(d) π/2I had been asked this question in examination.Question is from Angular Relation of a Sine Wave topic in section Introduction to Alternating Currents and Voltages of Network Theory

A sine wave completes quarter cycle in ____ radians.(a) 2π(b) π(c) π/2(d) π/4The question was asked at a job interview.The origin of the question is Angular Relation of a Sine Wave in portion Introduction to Alternating Currents and Voltages of Network Theory

A sine wave completes half cycle in ____ radians.(a) π/2(b) π(c) π/4(d) 2πI got this question in an interview.My question is taken from Angular Relation of a Sine Wave in chapter Introduction to Alternating Currents and Voltages of Network Theory

The period of a sine wave is 40ms. What is the frequency?(a) 25(b) 50(c) 75(d) 100This question was posed to me in an online interview.This intriguing question originated from Angular Relation of a Sine Wave in chapter Introduction to Alternating Currents and Voltages of Network Theory

The relation between frequency and time period is?(a) f=1/T(b) f=T(c) f=1/T^2(d) f=1/T^3This question was posed to me in an internship interview.Origin of the question is Angular Relation of a Sine Wave in division Introduction to Alternating Currents and Voltages of Network Theory

The response of a second order system is?(a) pulse(b) saw tooth(c) square(d) sinusoidThe question was posed to me in an internship interview.I want to ask this question from Angular Relation of a Sine Wave topic in portion Introduction to Alternating Currents and Voltages of Network Theory