Circuit Theory Question Bank PDF

Question Bank Electric Circuit Theory Section A (MCQ) 1. i) Linear circuit obeys: a) superposition theorem b) thevenin’s theorem c) ohm’s law d) superposition principle ii) How to obtain Step...

Question Bank Electric Circuit Theory Section A (MCQ) 1. i) Linear circuit obeys: a) superposition theorem b) thevenin’s theorem c) ohm’s law d) superposition principle ii) How to obtain Step function from Impulse function? a) Differentiation b) Addition c) Integration d) Multiplication iii) How to obtain Ramp function from Step function? a) Differentiation b) Addition c) Integration d) Multiplication iv) Resistor is a... a) Bilateral element b) Unilateral element c) Active element d) passive element v) In case of constructing tie-set matrix the number of tie set will be equal to the: a) number of twigs b) number of trees c) no. of links d) no of branches vi) Algebraic sum of the column entries of an incidence matrix is : a) 1 b) -1 c) 0 d) 5 vii) Relation between twigs and links of a tree is : a)B-N+1 b)B+N+1 c)B-N-1 d)-B+N+1 viii) In case of constructing cut-set matrix the number of cut-set will be equal to the : a) number of twigs b) number of trees c) no. of links d)no of branches Page 1 of 30 ix) If the voltage-current characteristics is a straight line through the origin, then the element is said to be? a) Linear element b) Non-linear element c) Unilateral element d) Bilateral element x)The circuit in which current has a complete path to flow is called ______ circuit. a) short b) open c) closed d) open loop xi) The condition for symmetry in terms of Z-parameter for a two port network is: a) Z11 Z22=0 b) Z11=Z22 c) Z11=1/Z22 d) Z11+Z21=0 xii)The condition for symmetry in terms of ABCD parameter for a two port network is: a) A=D b) B=C c) A=B d) B xiii)Which parameters are widely used in transmission line theory: a) ABCD parameters b) Z-parameters c) h-parameters d) Y-parameters xiv) A two-port network is simply a network inside a black box and the network has only : a) two pairs of accessible terminals b)two terminals c) two pairs of ports d) none of the above xv) The h-parameters h11 and h12 are obtained by a) opening input terminals b) shorting output terminals c) opening output terminals d) shorting input terminals xvi) A low-pass filter (LPF) is a type of filter which : a) passes all low frequencies b) passes all frequencies up to cut-off frequency and stops all other frequencies to pass through c) stops all high frequencies d) passes Page 2 of 30 all frequencies above cut-off frequency and stops all other frequencies to pass through xvii) A high-pass filter (LPF) is a type of filter which : a) passes all low frequencies b) passes all frequencies up to cut-off frequency and stops all other frequencies to pass through c) stops all high frequencies d) passes all frequencies above cut-off frequency and stops all other frequencies to pass through xviii)Kirchoffs law is valid for : a)nonlinear circuit b)linear circuit c) both A and B d) none of these xix)The internal impedance of an ideal voltage source is: a)1 b)0 c)infinite d)none of these xx)The internal impedance of an ideal current source is : a)1 b)0 c) infinite d) none of these xxi) The nodal method of circuit analysis is based on: a)KCL and ohms law b)KCL and superposition c)KVL and superposition d)KVL and ohms law xxii) In nodal analysis it is assumed: a)All the branch currents leave the junction b)have all the branch currents enter the junction c)both A and B d) none of this xxiii)KCL is used to solve circuits with : a)Capacitors b)closed loops c)sufficient notes / junctions d)have none of these xxiv) have if a graph have endnotes then the number of branches a tree have will be: a)n - 1 b)n + 1 c)2n d)n + 2 xxv) The branch of a tree is known as: Page 3 of 30 a)CHORD b)TWIG c)CO- tree d)links xxvi) The number of branches connected to a node is called : a] degree of NODE b) reference NODE c) tree d) none of these xxvii) if a graph has N number of nodes then the number of cut- set for the graph will be: a) N + 1 b] N - 1 c] N d] 2N xxviii) The relation AD - BC = 1 ,Where A, B, C, D are the elements of a transmission matrix of network is valid for : a] passive but not reciprocal network b] any type of network c] passive and reciprocal network d] both active and passive network xxix) A band pass filter can also be designed by : a) cascading the high-pass filter with band-stop filter b) cascading the low- pass filter with band- stop filter c) cascading the low- pass filter and the high- pass filter d) none of these xxx) active filters use: a) diodes capacitors and inductors b)diodes and transistors c)some active and some passive components d)transistor inductors and resistors xxxi) an active filter contains 5 capacitors. What is the order of the filter? a 10 b) 6 c) 4 d) 5 xxxii) A periodic Function f(t) with time period T repeats itself after half time T/2. The Fourier series of f(t) would contain : a) odd harmonics terms only B] have cosine terms only C] sine terms only D] even harmonics terms only xxxiii) A function x(t) is said to be even if x(t) is equal to: a) x(t) b) x(-2t) c) x(-t) d) -x(t) xxxiv) A function x(t) is said to be odd. If x(-t) is equal to : a) -x(t) b) x(t) c) -x(2t) d)x(-2t) Page 4 of 30 xxxv) A circuit having neither emf nor any energy source is a) Active circuit b) passive circuit c) unilateral circuit d) bilateral circuit xxxvi) If a function is shifted by T, then it is correctly represented by a) f(t-T)u(t) b) f(t-T)u(t-T) c) f(t)u(t-T) d) (t-T)f(t-T) xxxvii) Unit step function is the first derivatives of a) Ramp b) impulse c) sinusoidal d) Parabolic xxxviii) Ramp function is given by a) f(t) = t2 b) f(t) = t1/2 c) f(t)= t d) f(t)= tn xxxix) The function f(t) in the figure below is: a) u(t) b) u(t-2) c) u(2-t) d) u(2t) xxxx) A practical current source is usually represented by a) A resistance in series with an ideal current source b) A resistance in parallel with an ideal current source c) A resistance in series with an ideal voltage source d) A resistance in parallel with an ideal voltage source xxxxi) If all the element in a particular network are linear, then superposition theorem will hold when the excitation system is a) DC only b) AC only c) either AC or DC d) Impulse xxxxii) A two port network defined by the relation I1= 2V1+ V2 and I2 = 2V1 + 3V2, then Z12 is a) -2 ohm b) -1 ohm c) -1/2 ohm d) -1/4 ohm xxxxiii) The condition of reciprocity of a two port network having different parameters Page 5 of 30 a) h12 = h21 b) A = D c) Z12= Z21 d) All of these xxxxiv)Which among the following represents the precise condition of reciprocity for transmission parameters? a. AB - CD = 1 b. AD – BC = 1 c. AC – BD = 1 d. None of the above xxxxv) A Current in a circuit is given by, I(S) = 2S+ 8/(S2 + 4S+ 12). If current flows through a 5 ohm resistor then power dissipated at t= 0 is a) 20 W b) 40 W c) 15 W d) 10 W xxxxvi) When a series RL circuit is connected to a voltage source V at t= 0; the current passing through the inductor L of t=0+ is, a) V/R b) infinite c) zero d) V/L xxxxvii) A ideal filter should have a) Zero attenuation in the pass band b) Infinite attenuation in the pass band c) Zero attenuation in the attenuation band d) Infinite attenuation in the attenuation band xxxxviii) A low pass filter with cut off frequency of 30 HZ is cascaded with a high pass filter with cutoff frequency of 20 HZ. The resultant system of filters will function as: a) An all pass filter b) an all stop filter c) an band reject filter d) an band pass filter xxxxix) A high pass filter is basically a) A differentiating circuit with low time constant b) A differentiating circuit with large time constant c) An integrating circuit with low time constant d) An integrating circuit with large time constant xxxxx) Which filter performs exactly the opposite to the band-pass filter? a) Band- reject filter b) Band-stop filter c) Band-elimination filter d) All of the mentioned. xxxxxi) For Tie-set matrix, if the direction of current is same as loop current, then we place ______ in the matrix. Page 6 of 30 a) +1 b) -1 c) 0 d) +1 or -1 xxxxxii) What is the direction of the cut-set? a) same as the direction of the branch current b) opposite to the direction of the link current c) same as the direction of the link current d) opposite to the direction of the branch current xxxxxiii)A mesh is a loop which contains ____ number of loops within it. a)1 b)2 c)3 d) no loop xxxxxiv) onsider the circuit shown below. Find the current flowing through 24Ω resistor. a)0.33 b)0.66 c)0 d) 0.99 xxxxxv) Consider the circuit shown below. Find the thevenin’s resistance between terminals A and B. Page 7 of 30 a)1 b)2 c)1.7 d) 2.7 xxxxxvi)The dependent sources are of _____________ kinds. a)5 b)2 c)3 d) 4 xxxxxvii)Which of the following is not an example of a linear element? a) Resistor b) Thermistor c) Inductor d) Capacitor xxxxxviii)Example of distributed element is ___________ a)Resistor b)Thermistor c)Semiconductor diode d) Transmission lines Section B (Short and Long answer type questions) Module 1 2. Obtain the equation of f(t) for the figure shown below: Page 8 of 30 [Module 1/CO1/Understand-IOCQ] 5 3. A triangular waveform is shown below. Find the component waveforms. [Module 1/CO1/Understand-IOCQ] 5 4. A function f(t ) is shown below , write its equation in terms of step functions. [Module 1/CO1/Understand-IOCQ] 5 5. Obtain the waveform of the figure below. [Module 1/CO1/Understand-IOCQ] 5 Page 9 of 30 6.A sawtooth pulse is shown below. Synthesise the waveform. [Module 1/CO1/Understand-IOCQ] 5 7.A wave equation given by : Draw the waveform. [Module 1/CO1/Understand-IOCQ] 5 Module 2 8.a) Define incidence matrix [Module 2/CO4/Remember-LOCQ] 2 b)For the graph shown below, find the complete incidence matrix. Module 2/CO4/Understand-LOCQ] 3 Page 10 of 30 9. A graph is shown in below fig. Find the tie-set and cut-set matrices and obtain the KCL and kvl equations. [Module 2/CO4/Understand-IOCQ] 5 10. In the tree-link graph of below fig develop the fundamental cut-set matrix. [Module 2/CO4/Understand-IOCQ] 5 11. a) Write the properties of a tree. [ Module 2/CO4/Remember-LOCQ] 3 b) Draw the incidence matrix of the following graph. Page 11 of 30 [ Module 2/CO2/Understand-LOCQ] 4 c)A reduced incidence matrix of a graph is given by Obtain the number of possible trees. [Module 2/CO4/Apply-IOCQ] 8 12) A graph is shown in the below fig, find the tie-set and cut-set matrices. [Module 2/CO4/Apply-IOCQ] 7 Module 3 13. a) Find the drop across RL. Page 12 of 30 [ Module 3/CO1/Apply-IOCQ] 5 b)In the below coupled circuit, find the input impedance as well as net inductance. [Module 3/CO1/Apply-IOCQ] 7 c) Establish the relationship between self inductances L 1,L2,mutual inductance M and co-efficient of coupling K. [Module 3/CO1/Remember-LOCQ] 3 14.Find the total inductance of the 3 series connected coupled coils as shown the fig below: Module 3/CO1/Understand-IOCQ] 5 Page 13 of 30 15. Find V2 in the circuit of below fig such that current in the left hand loop(loop1) is zero. Assume : [Module 3/CO1/Understand-IOCQ] 6 Module 4 16.Obtain the expression for current I(t) when the switch is moved from position 1 to position 2 at t=0. [Module 4/CO2/Apply-IOCQ] 8 17.a) State and explain Initial value and Final Value Theorem. [Module 4/CO2/Remember-IOCQ] 7 b) In the initial condition, K is closed and a steady state is reached in the following network. At t=0, th switched is opened, what is the current through the inductor? Page 14 of 30  [Module 4/CO2/Evaluate-HOCQ] 8 18) What is Impulse Function? Find its Laplace Transform. [ Module 4/CO2/Remember- IOCQ] 4 19) Obtain the Laplace Transform of eθtCos(ῳt). [ Module 4/CO2/Apply-IOCQ] 4 20) A function in s-domain is given below. Find the inverse laplace transform.. [Module 4/CO2/Remember-IOCQ] 5 21)Derive step current response of RC parallel ciurcuit. [Module 4/CO2/Remember-IOCQ] 4 22) In below fig. the battery voltage is applied for a steady state period. Obtain the complete expression for the current after closing the swich K. Assume R 1=1 ohm, R2=2ohm, L=1H, E=10 V. Page 15 of 30 [Module 4/CO2/Understand-IOCQ] 6 23) Obtain the equation of the square train web shown below. What is its Laplace Transformation? [Module 4/CO2/Understand-IOCQ] 5 24) A pulse waveform is shown in figure below obtain its Laplace transform. [Module 4/CO2/Understand-IOCQ] 5 25) Find the Laplace transform of the Triangular waveform shown in the fig: Module 4/CO2/Understand-IOCQ] 5 26. A function is given below in s- domain.Find f(t) using Heaviside formula. [Module 1/CO2/Understand-IOCQ] Page 16 of 30 [ Module 4/CO2/Understand-IOCQ] 5 27. For the circuit shown below obtain the current through the capacitor (C) at t=0+ following switching at t=0. Assume the capacitor to be initially discharged. [Module 4/CO2/Apply-IOCQ] 7 28. State and explain initial value and final value theorem in case of laplace transform. [Module 4/CO2/ Remember -IOCQ] 6 Module 5 29)a) Define Fourier Transform. How does Fourier transform differ from Laplace Transform.? [Module 7/CO2/ Remember -IOCQ] 4 b) For the square wave shown below, find the exponential fourier series. Module 1/CO2/Understand-IOCQ] 7 c) Explain Odd Symmetry and Even Symmetry of periodic waveforms. [ Module 5/CO2/ Remember -IOCQ] 4 Page 17 of 30 30.a)Determine the Fourier series expansion for the following waveform. [Module 5/CO2/ Apply -IOCQ] 6 b) Obtain the Fourier analysis of the waveform shown below: [Module 5/CO2/ Apply -IOCQ] 9 31.Find the Fourier transform for the following gate function. [Module 5/CO2/Understand-IOCQ] 7 32. Find the trigonometric fourier series for the waveform shown in the following fig: Page 18 of 30  Module 5/CO2/Apply-HOCQ] 8 Module 6 33. Assuming maximum power transfer from the source to R ,find the value of this amount of power in the below circuit. [Module 6/CO3/Understand-IOCQ] 7 34. Find R to have maximum power transfer in the below circuit. Also obtain the amount of the maximum power. [ Module 6/CO3/Apply-IOCQ] 8 35. Find the current through the1ohm resistor using Millman’s Theorem. Page 19 of 30 [Module 6/CO3/Understand-IOCQ] 5 36. Determine the current through the 5 ohm resistor in below circuit. [ Module 6/CO2/Understand-IOCQ] 7 37. State and explain superposition theorem with an example. [Module 6/CO3/Remember-LOCQ] 5 38. In the circuit shown below , find the Norton’s equivalent circuit at the left of terminals x-y. [ Module 6/CO3/Evaluate-HOCQ] 8 39.a) State and Explain Millman’s Theorem. Calculate the Load current I in the below circuit in Millmans’s Theorem. Page 20 of 30 [ Module 6/CO3/Apply-IOCQ] 2+6 b) What is the Power Loss in the 10ῼ resistor? Use Thevenins Theroem in the fig below. [Module 6/CO3/Apply-IOCQ] 7 40.a) Find the current and power dissipated in the 5 ohm resistor in the circuit shown below: [Module 6/CO3/ Apply –IOCQ] 5 Page 21 of 30 b) Find i0, i2 and the value of the dependent source: [ Module 6/CO3/ Apply -IOCQ] 6 c) State and Explain Maximum Powe Transfer Theorem. [ Module 6/CO3/Remember-IOCQ] 4 41.a)In the below fig, find the power loss in 1ohm resistor using Nortons theorem [Module 6/CO3/Understand-IOCQ] 7 b) Find Norton equivalent to the left of x-y terminal in the below fig. [Module 1/CO2/Understand-IOCQ] 8 42.a) Develop mesh equations for the network below and find the power absorbed by the 3 ohm resistor. Page 22 of 30 [Module 1/CO2/Understand-IOCQ] 5 b) Find Thevenins equivalent circuit of the network shown below across the load: [Module 6/CO3/ Apply -IOCQ] 5 c) Using Milmans theorem find the current in load ZL in the below fig. [ Module 6/CO3/Understand-IOCQ] 5 43. a)What is power loss in the 10 ohm resistor ? Use Thevenins theorem. Page 23 of 30 [Module 6/CO3/Understand-IOCQ] 5 b)Find v by Superposition theorem. [ Module 6/CO3/Understand-IOCQ] 7 c)State and explain Nortons Theorem. [ Module 6/CO3/Remember-LOCQ] 3 44.a) What resistance should be connected across x-y in the circuit shown below such that maximum power is developed across this load resistance? What is the amount of this maximum power? [Module 6/CO3/ Apply -IOCQ] 7 b)Find thevenin’s equivalent across x-y in the below circuit. Page 24 of 30  [Module 6/CO3/Evaluate-HOCQ] 8 45. a) Find the current through 3 ohm resistor in the circuit of below fig. using Norton’s theorem. Verify the result using Thevenin’s theorem. [ Module 6/CO3/Apply-IOCQ] 8 b) Find the current in 2 ohm resistor using Thevenin’s theorem in below fig. Verify the result by Norton’s theotem. [ Module 6/CO3/Understand-IOCQ] 7 Module 7 46.a) Find the Z parameters for the given circuit: Page 25 of 30 [Module 7/CO5/Apply-IOCQ] 8 b) Determine the Z parameters from the following circuit: [ Module 7/CO5/Apply-IOCQ] 7 47.a) Determine the Y parameters from the following circuit: [ Module 7/CO5/Apply-IOCQ] 8 b) Represent Z parameters in terms of h and ABCD parameters: [Module 7/CO5/Remember-LOCQ] 7 Page 26 of 30 48.a) A π network has been shown in fig , where 0.5I 3 is a controlled current source. Obtain the Z parameters for the π circuit model. [Module 6/CO3/Apply-IOCQ] 9 b)For the following h parameter equivalent network find the voltage gain. Assume the load resistance to be RL. [Module 7/CO2/Apply-IOCQ] 6 49. a) Find out the overall ABCD parameter network matrix for two numbers of two port network which are connected in cascade. [ Module 7/CO5/Remember-IOCQ] 7 b) Obtain the open circuit parameters and loop equations of the network shown below. Page 27 of 30 [Module 7/CO5/Apply-IOCQ] 8 50.Find the y paremeters for the following network shown in the fig: Module 7/CO5/Understand-IOCQ] 5 51.Find Z parameters for the Lattice network shown below: [Module 7/CO5/Apply-IOCQ] 7 52.Determine the Z parameters of the network showbn below. Page 28 of 30 [Module 7/CO5/Apply-IOCQ] 7 53.Prove that AD-BC=1. [Module 7/CO5/Remember-LOCQ] 5 54.Find ABCD parameters in terms of Z and Y parameter. [Module 7/CO5/Remember-LOCQ] 5 Module 8 55.a) What are the advantages of Active filter over Pasiive filter? [Module 8/CO6/ Remember -LOCQ] 4 b) Design a High Pass Active filter of cut-off frequency 1kHz with a Pass-band gain of 2. [ Module 8/CO6/Create-HOCQ] 5 c)Draw the circuit diagram of a first order low pass filter and find out the expression of the cut-off frequency. [Module 8/CO6/ Remember -IOCQ] 6 Page 29 of 30 Page 30 of 30