105 + Interview Questions in Inductance In A Dc Circuit in Basic Electrical Engineering Page 1 InterviewSolution

1.	Find the value of x if the Mutual inductance is 20H, the inductance of coil 1 is xH and the inductance of coil 2 is 8H. The coupling coefficient is 5.(a) 2H(b) 4H(c) 6H(d) 8HThe question was posed to me during an internship interview.My question comes from Coupling Coefficient in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT ANSWER is (a) 2H Best explanation: we know that: k=M/sqrt(L1L2) Substituting the values from the QUESTION, we GET L1=2H.

Discussion

2.	Which, among the following, is the correct formula to find the coupling coefficient?(a) k=M/sqrt(L1L2)(b) k=M/sqrt(L1^2)(c) k=M/sqrt(L2^2)(d) k=M/(L1L2)The question was posed to me by my school teacher while I was bunking the class.The above asked question is from Coupling Coefficient in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Right answer is (a) k=M/sqrt(L1L2) To elaborate: The correct FORMULA for the COUPLING coefficient is k=M/sqrt(L1L2). Where L1 and L2 are the inductance VALUES of the first and SECOND coil respectively and M is the mutual inductance.

Discussion

3.	If the flux linkage in coil 1 is 3Wb and it has 500 turns and the current in coil 2 is 2A, calculate the mutual inductance.(a) 750H(b) 500H(c) 450H(d) 900HThis question was posed to me in an online quiz.My doubt is from Mutual Inductance topic in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT option is (a) 750H The best I can explain: We know that mutual inductance is the product of the number of turns in ONE coil and the FLUX linkages of that coil, DIVIDED by the current in the other coil. M=3*500/2=750H.

Discussion

4.	Initially, when the switch in a series RL circuit is closed, the current in the inductor is?(a) Maximum(b) Minimum(c) Zero(d) InfinityI got this question during a job interview.My query is from Transients in LR Networks in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The CORRECT OPTION is (c) Zero To elaborate: Initially, when the switch in a SERIES RL circuit is closed, the inductor acts as an open circuit. CURRENT in an open circuit is zero, hence the inductor current is zero.

Discussion

5.	If the switch is opened at t=0, what is the current in the circuit?(a) 0A(b) 1A(c) 2A(d) 3AThe question was posed to me during an interview.The origin of the question is Transients in LR Networks topic in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct ANSWER is (c) 2A The BEST I can explain: Initially when SWITCH was closed,current in the INDUCTOR was 60/30=2A. Current in inductor doesn’t change SUDDENLY so when switch is opened, current in inductor remains same i.e. 2A.

Discussion

6.	A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the final value of the current in the circuit.(a) 5A(b) 10A(c) 15A(d) 20AThe question was posed to me at a job interview.The question is from Analysis of Growth & Decay in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT choice is (a) 5A The best EXPLANATION: The final value of the current in the circuit is: I=V/R = 5A.

Discussion

7.	What is the expression for voltage in the given circuit?(a) V=60e^-0.5t(b) V=30e^-0.5t(c) V=60e^-2t(d) V=30e^-2tThe question was posed to me by my college director while I was bunking the class.My doubt is from Transients in LR Networks in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct CHOICE is (c) V=60e^-2t To ELABORATE: Applying KVL in above CIRCUIT, we get 60-30i-15di/dt = 0 i=2(1-e^-2t)A di/dt = 4e^-2t V=Ldi/dt=15*4e-^-2t=60e^-2t.

Discussion

8.	What is the energy stored in the magnetic field if the current in a coil has a constant inductance of L henrys grows at a uniform rate?(a) LI/2(b) LI^2/2(c) L/2I(d) L/2I^2The question was posed to me in an interview.My question comes from Energy Stored in an Inductor in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT choice is (b) LI^2/2 The explanation: EMF induced in the COIL is Ldi/dt. Energy=eidt=Lidi/dtdt=Li^2/2.

Discussion

9.	Initially, when the switch in a series RL circuit is closed, the inductor acts as?(a) Open circuit(b) Short circuit(c) Resistor(d) CapacitorThis question was addressed to me by my school principal while I was bunking the class.Query is from Transients in LR Networks topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT answer is (a) Open circuit Explanation: Before switch is closed, current in INDUCTOR is zero. When the switch in a series RL circuit is closed, current in the inductor remains zero since current in inductor doesn’t change suddenly. So, the inductor acts as an open circuit.

Discussion

10.	At steady state, the current in the inductor is?(a) Maximum(b) Minimum(c) Zero(d) InfinityI had been asked this question during a job interview.Enquiry is from Transients in LR Networks in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT option is (a) Maximum The explanation is: At steady state maximum CURRENT flows in the inductor because it acts as an OPEN CIRCUIT.

Discussion

11.	If the current changes from 5A to 3A in x sec and inductance is 10H. The emf is 10V, calculate the value of x.(a) 2s(b) 3s(c) 4s(d) 5sI got this question in exam.Question is from Inductance in Terms of Flux Linkages Per Ampere topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct CHOICE is (a) 2s To ELABORATE: We know that: emf=L(i2-i1)/t Substituting the VALUES from the QUESTION, we get x=2s.

Discussion

12.	In an RL series circuit, when the switch is closed and the circuit is complete, what is the response?(a) Response does not vary with time(b) Decays with time(c) Increases with time(d) First increases, then decreaseI had been asked this question in exam.This key question is from Transients in LR Networks topic in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» CORRECT choice is (b) Decays with time The BEST I can explain: In an RL series CIRCUIT, the response decays with time because according to the EQUATION, there is an exponential DECREASE in the response.

Discussion

13.	Find voltage across 12H inductor.(a) 2V(b) 10V(c) 12V(d) 20VI had been asked this question in a national level competition.This intriguing question originated from Coils Connected in Series in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct OPTION is (c) 12V To elaborate: e=Ldi/dt Leq=2+10+12+20=44H di/dt=44/44 = 1 A/s. Voltage ACROSS 12H INDUCTOR = 12di/dt = 121=12V.

Discussion

14.	Find the time taken for the current in an inductor to change to 2A from 0A if the power in the inductor is 5W. The value of inductance is 10H.(a) 1s(b) 2s(c) 3s(d) 4sI have been asked this question in an interview for internship.The doubt is from Energy Stored in an Inductor topic in division Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Correct CHOICE is (d) 4s The explanation is: The expression for power in an INDUCTIVE circuit is: P = LI^2/2t Substituting the VALUES from the GIVEN question, we GET t=4s.

Discussion

15.	If the current in one coil is steady, what happens to the mutual inductance?(a) Zero(b) Infinity(c) Doubles(d) HalvesI had been asked this question in an international level competition.This interesting question is from Mutual Inductance in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Correct OPTION is (a) Zero The explanation: A current is induced when there is CHANGING magnetic flux. The induced current in NEIGHBOURING COIL is zero when the current is steady. So, mutual inductance is zero.

Discussion

16.	Calculate the power in an inductive circuit if the inductance is 10H, the current flowing in the inductor is 2A in 4s.(a) 50W(b) 4W(c) 5W(d) 10WI had been asked this question in a national level competition.My question is from Energy Stored in an Inductor in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Correct CHOICE is (c) 5W Easy EXPLANATION: The expression for POWER in an INDUCTIVE circuit is: P = LI^2/2t Substituting the VALUES from the given question, we get P=5W.

Discussion

17.	A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the value of current 1s after the switch is closed.(a) 5.44A(b) 4.32A(c) 6.56A(d) 2.34AI had been asked this question in an interview.My enquiry is from Analysis of Growth & Decay topic in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» CORRECT choice is (b) 4.32A The EXPLANATION: We KNOW that: i=I(1-e^Rt/L) I=V/R=5A Substituting the REMAINING values from the given question, we get i=4.32A.

Discussion

18.	What happens to the inductance when the current in the coil becomes double its original value?(a) Becomes half(b) Becomes four times(c) Becomes double(d) Remains sameI got this question in an online interview.Origin of the question is Factors Determining the Inductance of a Coil in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Right choice is (d) Remains same To ELABORATE: ϕ is directly proportional to i. Φ=Li where L is constant of proportionality So, when current get double ϕalso becomes double KEEPING L same.

Discussion

19.	For a coil having a magnetic circuit of constant reluctance, if the flux increases, what happens to the current?(a) Increases(b) Decreases(c) Remains constant(d) Becomes zeroThe question was posed to me by my college professor while I was bunking the class.My question is based upon Inductance in Terms of Flux Linkages Per Ampere topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct answer is (a) INCREASES To ELABORATE: For a coil having a magnetic circuit of constant reluctance, the flux is directly proportional to the CURRENT. HENCE as the flux increases, the current also increases.

Discussion

20.	The unit for inductance is ___________(a) Ohm(b) Henry(c) A/m(d) A/sThis question was posed to me in an internship interview.My question is taken from Inductance in Terms of Flux Linkages Per Ampere in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct answer is (b) Henry To elaborate: The UNIT of induction is named after a famous SCIENTIST JOSEPH Henry who INDEPENDENTLY discovered electromagnetic induction.

Discussion

21.	For a coil having a magnetic circuit of constant reluctance, the flux is ___________ to the current.(a) Directly proportional(b) Inversely proportional(c) Not related(d) Very large compared toThis question was posed to me by my college director while I was bunking the class.This intriguing question originated from Inductance in Terms of Flux Linkages Per Ampere topic in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» CORRECT choice is (a) DIRECTLY proportional Easy explanation: For a coil having a MAGNETIC circuit of constant reluctance, the flux is directly proportional to the CURRENT.

Discussion

22.	If the power factor is 1/10 and the value of impedance is 20 ohm, calculate the resistance in the circuit.(a) 1 ohm(b) 2 ohm(c) 3 ohm(d) 4 ohmI have been asked this question in an interview.My question is based upon Inductive and Non-Inductive Circuits topic in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct choice is (b) 2 OHM To EXPLAIN I would SAY: We KNOW that: COS(ϕ)=R/Z R=Z cos(ϕ) = 20/10 = 2 ohm.

Discussion

23.	If the current and voltage are 90 degrees out of phase, the power factor will be?(a) 0(b) Infinity(c) 1(d) Insufficient information providedThis question was addressed to me during an interview.This interesting question is from Inductive and Non-Inductive Circuits in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Right choice is (a) 0 To explain I WOULD say: The power factor is the cosine of the ANGLE between the voltage and the current. If the angle between the voltage and the current is 90, then cos90=0. Hence, the power factor is zero.

Discussion

24.	In a pure inductive circuit, the power factor is __________(a) Maximum(b) Minimum(c) 0(d) InfinityThis question was addressed to me in unit test.This key question is from Inductive and Non-Inductive Circuits topic in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Correct OPTION is (C) 0 Explanation: In a pure inductive circuit, the current is LAGGING by 90 degrees from the VOLTAGE. The power FACTOR is the cosine of the angle between the voltage and the current. If the angle between the voltage and current is 90, then cos90=0. Hence, the power factor is zero.

Discussion

25.	Find the coupling coefficient if the Mutual inductance is 20H, the inductance of coil 1 is 2H and the inductance of coil 2 is 8H.(a) 5(b) 20(c) 2(d) 8The question was posed to me by my school teacher while I was bunking the class.Query is from Coupling Coefficient topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Right choice is (a) 5 Easiest explanation: we KNOW that: k=M/sqrt(L1L2) SUBSTITUTING the values from the QUESTION, we GET k=5.

Discussion

26.	In a series circuit, which of the parameters remain constant across all circuit elements such as resistor, capacitor, inductor etc?(a) Voltage(b) Current(c) Both voltage and current(d) Neither voltage nor currentThe question was asked in my homework.This key question is from Coils Connected in Series topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Correct answer is (b) Current The EXPLANATION: In a series CIRCUIT, the current across all ELEMENTS remain the same and the total voltage of the circuit is the sum of the VOLTAGES across all the elements.

Discussion

27.	The flux linkage in coil 1 is 3Wb and it has x turns and the current in coil 2 is 2A, calculate the value of x if the mutual inductance is 750H.(a) 300(b) 400(c) 500(d) 700This question was posed to me in an international level competition.My enquiry is from Mutual Inductance topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct option is (c) 500 Easiest EXPLANATION: We know that MUTUAL INDUCTANCE is the product of the number of turns in ONE coil and the flux LINKAGES of that coil, divided by the current in the other coil. N=750*2/3 = 500 turns.

Discussion

28.	A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the value of voltage 1s after the switch is closed.(a) 5.4V(b) 10.8V(c) 0 V(d) 2.7VThe question was posed to me by my college director while I was bunking the class.My question is from Analysis of Growth & Decay topic in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT CHOICE is (d) 2.7V For EXPLANATION: V=V0e^-Rt/L V=20e^-2=2.7V.

Discussion

29.	The charging time constant of a circuit consisting of an inductor is the time taken for the voltage in the inductor to become __________ % of the initial voltage.(a) 33(b) 63(c) 37(d) 36I had been asked this question during an interview for a job.My question is from Growth in an Inductive Circuit in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT answer is (c) 37 For explanation: We know that: V=V0(1-e^-tR/L). When time CONSTANT=t, we have: V=V0(1-e^-1) = 0.37*V0. Hence the time constant is the time TAKEN for the charge in an inductive CIRCUIT to become 0.37 TIMES its initial charge.

Discussion

30.	What happens to the current when a ferromagnetic material is introduced within an inductor?(a) Increases(b) Decreases(c) Remains the same(d) Becomes zeroI got this question by my college professor while I was bunking the class.Question is taken from Ferromagnetic Cored Inductor in a DC Circuit in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Right option is (c) Remains the same To ELABORATE: When a ferromagnetic is introduced within an INDUCTOR, the current remains fairly CONSTANT. This is because the current does not depend on the magnetic FIELD.

Discussion

31.	If the current changes from 5A to 3A in 2 seconds and the inductance is 10H, calculate the emf.(a) 5V(b) 10V(c) 15V(d) 20VThe question was posed to me during an internship interview.This intriguing question originated from Inductance in Terms of Flux Linkages Per Ampere topic in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» CORRECT CHOICE is (B) 10V To explain I would say: We know that: emf=L(i2-i1)/t Substituting the values from the QUESTION, we GET emf=10V.

Discussion

32.	In case of Inductive circuit, Frequency is ______________ to the current.(a) Directly proportional(b) Inversely proportional(c) Unrelated(d) Much greater thanI had been asked this question during an interview.My query is from Inductive and Non-Inductive Circuits in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Right OPTION is (b) Inversely proportional To EXPLAIN I would say: The formula for frequency in an INDUCTIVE circuit is: XL=2πfL =>i=V/(2πfL) Therefore: f is inversely proportional to i.

Discussion

33.	Mutual inductance between two coupled coils depend on?(a) Amount of flux linkage(b) Rate of change of flux linkage(c) Rate of change of current(d) Flux densityThe question was posed to me in final exam.Asked question is from Coupling Coefficient topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» CORRECT answer is (b) RATE of change of flux linkage The EXPLANATION is: FARADAY’s law of induction states that the magnitude of the induced EMF is the product of the number of turns of the coil and the rate of change of flux linkage in it. Hence, the mutual inductance depends on the rate of change of flux linkage.

Discussion

34.	Can the coupling coefficient practically ever be equal to 1?(a) Yes(b) No(c) Depends on the current in coil 1(d) Depends on the current in coil 2This question was addressed to me during an internship interview.The origin of the question is Coupling Coefficient topic in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT answer is (b) No Best explanation: All the flux of coil 1 can NEVER link with coil 2. Loss occurs PRACTICALLY due to which coupling coefficient cannot be equal to 1.

Discussion

35.	When the coil is wrapped around a ferromagnetic core, why is it difficult to determine the inductance?(a) The variation of flux is no longer proportional to the variation of current(b) Current does not exist in the coil(c) Flux does not exist in the coil(d) The value of current is too large to measureI had been asked this question in final exam.My question is from Factors Determining the Inductance of a Coil in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct answer is (a) The variation of flux is no longer proportional to the variation of CURRENT Best explanation: When a coil is WRAPPED around a ferromagnetic core, it is DIFFICULT to determine the INDUCTANCE because the variation of flux is no longer proportional to the variation of the current.

Discussion

36.	Three inductors having inductance values 3H, 4H and 5H are connected in series, calculate the equivalent inductance.(a) 10H(b) 12H(c) 3H(d) 5HI had been asked this question in exam.My question is taken from Coils Connected in Series topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct choice is (b) 12H The best explanation: When inductances are connected in series, the EQUIVALENT inductance is EQUAL to the sum of all the INDIVIDUAL inductance values. Hence LEQ= L1+L2+L3= 12H.

Discussion

37.	Find the value of x if the Mutual inductance is x H, the inductance of coil 1 is 2H and the inductance of coil 2 is 8H. The coupling coefficient is 5.(a) 10H(b) 20H(c) 16H(d) 15HI got this question in an internship interview.This question is from Coupling Coefficient topic in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct option is (B) 20H The BEST explanation: we KNOW that: k=M/sqrt(L1L2) Substituting the values from the QUESTION, we GET M=20H.

Discussion

38.	Calculate the value of stored energy in an inductor if the value of inductance is 20H and 4A of current flows through it.(a) 220J(b) 150J(c) 190J(d) 160JI had been asked this question in an online quiz.This question is from Energy Stored in an Inductor in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The CORRECT choice is (d) 160J For EXPLANATION I WOULD SAY: The expression for energy in an inductor is E = LI^2/2. Substituting the VALUES from the given question, we get E = 160J.

Discussion

39.	Find the average current in an inductor if the total current in the inductor is 26A.(a) 10A(b) 26A(c) 13A(d) 5AI had been asked this question by my college professor while I was bunking the class.This interesting question is from Energy Stored in an Inductor topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT OPTION is (C) 13A Explanation: Average current = I/2. Substituting the value of I from the EQUATION, average current = 13A.

Discussion

40.	What is the voltage across the inductor at t=0?(a) 0V(b) 20V(c) 60V(d) 58VI had been asked this question in final exam.The doubt is from Transients in LR Networks in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Right option is (c) 60V Easiest EXPLANATION: Initially, when the switch is OPEN, the CURRENT in the circuit is 0. As SOON as the switch is closes at t=0+, the inductor acts as an open circuit, HENCE the current in the circuit is zero. Since the current in the circuit is zero, there is no voltage drop across the resistor and the voltage across the inductor is equal to the supply voltage, which is equal to 60V.

Discussion

41.	A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the initial value of the current in the circuit.(a) 5A(b) 10A(c) 0 A(d) 20AThe question was posed to me in an international level competition.This interesting question is from Analysis of Growth & Decay topic in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Right CHOICE is (c) 0 A Easiest explanation: Initially, INDUCTOR behave as OPEN circuit for dc CURRENT so, i=0.

Discussion

42.	Calculate the inductance in an inductive circuit whose time constant is 2s and the resistance is 5 ohm.(a) 10H(b) 20H(c) 5H(d) 15HI got this question during an online exam.Enquiry is from Growth in an Inductive Circuit in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct ANSWER is (a) 10H Easy EXPLANATION: We know that: Time constant = L/R Substituting the VALUES from the given question, we get L=10H.

Discussion

43.	What is the time constant of an inductive circuit?(a) LR(b) R/L(c) 1/LR(d) L/RI have been asked this question in homework.Query is from Growth in an Inductive Circuit topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct option is (d) L/R The BEST explanation: The time CONSTANT in an INDUCTIVE circuit is the time taken for the voltage across the INDUCTOR to become 63 percent of its initial value. It is GIVEN by Time constant = L/R.

Discussion

44.	What happens to the inductance as the length of the magnetic circuit increases?(a) Increases(b) Decreases(c) Remains the same(d) Becomes zeroI got this question in an internship interview.My query is from Factors Determining the Inductance of a Coil topic in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Correct option is (b) DECREASES Explanation: L=µ0N^2A/l, HENCE as the LENGTH of the magnetic CIRCUIT l increases, the inductance decreases.

Discussion

45.	If the current changes from 3A to 5A in 2s and the emf is 10V. Calculate the inductance.(a) 10H(b) 20H(c) 30H(d) 40HThe question was posed to me in unit test.This intriguing question comes from Inductance in Terms of Flux Linkages Per Ampere topic in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Right OPTION is (a) 10H The best I can explain: If the current changes from 5A to 3A in 2s and the EMF is 10V. CALCULATE the INDUCTANCE.

Discussion

46.	Among the following, which is the right formula for inductance?(a) L=emft/I(b) L=emf/tI(c) L=emfI/t(d) L=emft*II got this question by my college director while I was bunking the class.I'd like to ask this question from Inductance in Terms of Flux Linkages Per Ampere topic in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Right ANSWER is (a) L=emft/I Easy explanation: The average emf INDUCED is PROPORTIONAL to the current PER unit time, the constant of proportionality being L. Hence emf=LI/t. Making L the SUBJECT of the formula, we get L=emft/I.

Discussion

47.	An induced emf is said to be ________(a) Inductive(b) Capacitive(c) Resistive(d) Cannot be determinedThe question was asked in semester exam.Origin of the question is Inductive and Non-Inductive Circuits in section Inductance in a DC Circuit of Basic Electrical Engineering
Answer» RIGHT ANSWER is (a) Inductive To ELABORATE: Any circuit in which a CHANGE of current is ACCOMPANIED by a change of flux, and therefore by an induced emf, is said to be inductive.

Discussion

48.	When inductances are connected in series, the equivalent inductance is ____________ the largest individual inductance.(a) Greater than(b) Less than(c) Equal to(d) Not related toI had been asked this question in homework.My question is from Coils Connected in Series topic in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Correct CHOICE is (a) Greater than Explanation: When INDUCTANCES are connected in series, the equivalent INDUCTANCE is equal to the sum of all the individual inductance VALUES. HENCE the equivalent inductance is greater than the largest individual inductance.

Discussion

49.	If the current in a coil having a constant inductance of L henrys grows at a uniform rate, what is the value of the average current?(a) I(b) I/2(c) I/4(d) 0The question was asked in an internship interview.I want to ask this question from Energy Stored in an Inductor in chapter Inductance in a DC Circuit of Basic Electrical Engineering
Answer» Correct option is (B) I/2 The best I can EXPLAIN: The average CURRENT is the average of the current which flows in the inductor. HENCE it is I/2.

Discussion

50.	A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the final value of the voltage across the inductor.(a) 5V(b) 10V(c) 0 V(d) 20VThe question was asked in an interview for job.The origin of the question is Analysis of Growth & Decay in portion Inductance in a DC Circuit of Basic Electrical Engineering
Answer» The correct answer is (c) 0 V To elaborate: At STEADY STATE, inductor behaves as a SHORT CIRCUIT for dc current so, V=0

Discussion

Explore topic-wise InterviewSolutions in .

Initially, when the switch in a series RL circuit is closed, the current in the inductor is?(a) Maximum(b) Minimum(c) Zero(d) InfinityI got this question during a job interview.My query is from Transients in LR Networks in portion Inductance in a DC Circuit of Basic Electrical Engineering

If the switch is opened at t=0, what is the current in the circuit?(a) 0A(b) 1A(c) 2A(d) 3AThe question was posed to me during an interview.The origin of the question is Transients in LR Networks topic in portion Inductance in a DC Circuit of Basic Electrical Engineering

At steady state, the current in the inductor is?(a) Maximum(b) Minimum(c) Zero(d) InfinityI had been asked this question during a job interview.Enquiry is from Transients in LR Networks in portion Inductance in a DC Circuit of Basic Electrical Engineering

Find voltage across 12H inductor.(a) 2V(b) 10V(c) 12V(d) 20VI had been asked this question in a national level competition.This intriguing question originated from Coils Connected in Series in portion Inductance in a DC Circuit of Basic Electrical Engineering

The unit for inductance is ___________(a) Ohm(b) Henry(c) A/m(d) A/sThis question was posed to me in an internship interview.My question is taken from Inductance in Terms of Flux Linkages Per Ampere in chapter Inductance in a DC Circuit of Basic Electrical Engineering

In a pure inductive circuit, the power factor is __________(a) Maximum(b) Minimum(c) 0(d) InfinityThis question was addressed to me in unit test.This key question is from Inductive and Non-Inductive Circuits topic in chapter Inductance in a DC Circuit of Basic Electrical Engineering

What is the voltage across the inductor at t=0?(a) 0V(b) 20V(c) 60V(d) 58VI had been asked this question in final exam.The doubt is from Transients in LR Networks in portion Inductance in a DC Circuit of Basic Electrical Engineering

Calculate the inductance in an inductive circuit whose time constant is 2s and the resistance is 5 ohm.(a) 10H(b) 20H(c) 5H(d) 15HI got this question during an online exam.Enquiry is from Growth in an Inductive Circuit in section Inductance in a DC Circuit of Basic Electrical Engineering

What is the time constant of an inductive circuit?(a) LR(b) R/L(c) 1/LR(d) L/RI have been asked this question in homework.Query is from Growth in an Inductive Circuit topic in section Inductance in a DC Circuit of Basic Electrical Engineering

An induced emf is said to be ________(a) Inductive(b) Capacitive(c) Resistive(d) Cannot be determinedThe question was asked in semester exam.Origin of the question is Inductive and Non-Inductive Circuits in section Inductance in a DC Circuit of Basic Electrical Engineering