BASIC ELECTRICAL ENGINEERINGUNIT I D.C.CIRCUITS 11 hrs.Electrical quantities, Ohm’s Law, Resistors - Series and parallel combinations, Kirchoff’s laws, Node and Mesh Analysis - Star delta Transformation1.Define average value of voltage.2.State Ohms law.3.State Kirchoffs I and II Law. State Kirchhoff’s Laws.4.Define electrical power./ Differentiate between electrical power and energy. 5.Define specific resistance/ Define electric resistance. 6.Write down the voltage division and current division rule.7.Compare series and Parallel circuits./ (a) Differentiate series and parallel circuit.8.Write the expression for the equivalent star network resistance for a given delta network.9.Define Electrical Resistance and give its unit. 10.Give any two differences between series and parallel circuit11.Derive the expression for equivalent resistance when two resistance are connected in parallel.12.Define electric current.13.State the difference between electrical power & energy.14.Define electrical current, potential in an electric circuit.15.Write the formula for transformation of delta to star.16.A resistance, immersed in oil, has 62.5 resistance and is connected to 500V d.c. supply.Calculate the power in watts.17.A circuit consists of two resistances, R1 and R2, in parallel. The total current passing through the circuit is IT. Give the equation for the current passing through R1.Define electric potential.A current in a circuit is due to a 20 V of applied voltage to a resistor of 200 Ω. What resistance would permit the same current to flow if the applied voltage were 200 V? (b) Find the equivalent resistance when the following resistances are connected in series and parallel(i) 20 k Ω and 40 k Ω(ii) 4 Ω, 8 Ω and 16 Ω (iii) 800 Ω,4 k Ω and 1500 Ω18. Find the power supplied by the battery.

19.Two coils connected in parallel across a 100V, dc supply draw a current of 9A. The power dissipated in one coil is 500W. Find the resistance of the two coils and the current in each coil.

20.Find the current flowing through 5 resistors

21.A circuit consists of two resistances, R1 and R2, in parallel. The total current passing through the circuit is IT. Give the equation for the current passing through R1.Given the circuit in Fig.1, determine the current I3 and the voltage V0 across the current source.

22.For the given circuit determine the currents in all resistors.

23.Two batteries A and B with internal resistances of 5 and 3 respectively are connected in parallel across a load of 25. The emfs of A and B are 100V and 150V respectively. Using Kirchoffs laws determine the magnitude and direction of currents in each of the batteries and also in the load resistance.

24.Find (a) the current in the 15 ohm resistor –M-12(b) voltage across 18 ohm resistor and (c) power dissipated in 7 ohm resistor of the given circuit.

Find the current in the 2 resistor shown using loop analysis: (8)

25.Given the circuit in Fig.1, determine the current I3 and the voltage V0 across the current source.

26.Derive the expression to finda) Star resistance in terms of Deltab) Delta resistance in terms of star27. Give the expression for star to delta and delta to star transformations. M-12

(b) Convert the networks given in the figure to equivalent star and delta networks-M-12

28.Determine the equivalent resistance across AB of the circuit shown in figure.

29.An electrical network is arranged as shown in fig.1. Find (a) the current in branch AF (b) the power absorbed in branch BE and (b) P.D across branch CD.

30.Determine the current I for the given circuit

31. Using star – delta transformation find the current I supplied by the battery in fig.2.

32.Determine the value of R if the power dissipated in 10 ohms resistor is 90W.33.For the given circuit, calculate the load current IL and power consumed by RL.

80 ohms

R

50V

2 A 10 ohms

100 ohms

2 A

40 ohms

34.Using star-delta transformation, find the current through 4.5k resistor in Fig.3.

35.Write the Mesh Current equations and determine the value of Currents.Draw Diagram

36.Determine the mesh currents in the given circuit.

(a) Using star – delta transformation find the current I supplied by the battery in fig.2.

37.Write the mesh equations for the circuit shown in Fig.2 and determine the currents I1, I2, and I3.

38.Use mesh analysis to find i1 in the circuit shown, if element A is a 5 resistor.

39.Find the current through 6 resistor for the circuit using ‘mesh current’ method and hence calculate the voltage across the current source.

40.Write the mesh equations for the circuit shown in Fig.2 and determine the currents I1, I2, and I3.

41.Using Mesh current analysis, find the current through the galvanometer G in the wheatstone bridge shown in fig.2

42.A network is arranged as shown in the fig. determine the value of current in the 8 ohm resistor using Mesh equations.

42.Write the node voltage equation and determine the current in each branch of the network.Draw diagram.

42.Use nodal voltage method and find the power dissipated in the 8 ohms resistor on the circuit shown in the figure.2

ohms830V

ohms4

2 ohms2 ohms 4 ohms

20V

43.Use nodal analysis to find all the branch currents in the circuit in Fig.4.

44.Use nodal analysis to find all the branch currents in the circuit in Fig.4.

UNIT II MAGNETIC CIRCUITS 8 hrs.Definition of MMF, Flux and reluctance - Leakage factor - Reluctances in series and parallel (series and parallel magnetic circuits) - Electromagnetic induction - Fleming’s rule - Lenz’s law - Faraday’s laws - statically and dynamically induced EMF - Self and mutual inductance - Energy stored and energy density - Analogy of electric and magnetic circuits1. Define magneto motive force.2. Define magnetic field strength3.What is flux? Give its unit. / Define flux and flux density.4.Define Leakage factor5.Define reluctance/ Define Reluctance.. (a) What is reluctance? (2)6. Define reluctance of magnetic circuit7.State Faraday’s law./ State Faraday’s law. Briefly describe the significance of the law8.Define the term leakage flux and leakage factor.9. Write the expression for ohm's law of magnetism.10. Define Lenz’s Law.11. State Flemmings right hand rule./ a) State Fleming Rule and Lenz’s Law12. Define Fleming’s Right Hand Rule.13.Compare statically and dynamically induced emfs./ Write a brief note on statistically induced emf and dynamically induced emf.-M-1114.The combined inductance of two coils connected in series is 1.2 H or 0.2 H, depending on the relative directions of the currents in the coils. If one the coils, when isolated, has a self inductance of 0.4 H, calculate Mutual inductance and coupling coefficient.15.Compare Electric and Magnetic circuits with their electrical quantities/(a) Compare Magnetic circuits & Electric circuits. .-Do-11/. (b) Compare electric and magnetic circuits.16. Derive the expression for hysteresis loss by also explaining B-H curve.=m/1317.a) Explain the concept of mutual and self inductance and define the units in which these are measured./ Explain the concepts of mutual and self inductance./ (b) What do you mean by mutual Induction? Define mutual Induction with its units/(b) Derive the expressions for the self and mutual inductance and explain them with suitable examples./ (a) Explain the concept of Mutual inductance. /(a) Explain the concept of mutual inductance.-Mo-11/ Define the concept of electromagnetic induction and derive the expression for Self and Mutual inductance=M-12/(a) Write short notes on electromagnetic induction. Mo-11/ What is electromagnetic induction? Briefly explain self and mutual inductance

18.Derive the necessary expression for calculating the inductance of a coil.19.(b) Explain the types of induced emfs-Do-12/) Explain the types of induced emfs/. State self and mutual inductance and derive the expression for the same.20.Define the terms =M-12

(a) MMF (b) Flux (c) Reluctance (d) Faraday’s law (e) Lenz law (f) Fleming’s right and left hand rule.

21.(a) State the given laws (i) Faraday’s law (ii) Lenz law (iii) Fleming’s right and left hand rule. (b) Give the analogy between Electric and Magnetic circuit./ (a) Explain the analogy of electric and magnetic circuits.-Do-10

22.State Faraday’s law of electromagnetic induction. Explain about Statically and Dynamically induced EMF.-D-10/(a) Describe the Faraday’s Law of Electromagnetic Induction with neat diagram. Do-10/ State and explain Faraday's laws of electromagnetic induction, Lenz's law, Fleming's right hand and left hand rule.

22.(a) Explain the calculation of reluctance in series and parallel circuits/23.A ring has mean diameter of 15cm, a cross section 1.7cm2 and a radial gap of 0.5 mm cut in it. It is uniformly wound with 1500 turns of insulated wire and a current of 1 ampere produces a flux of 0.1 mwb at the gap. Calculate relative permeability of iron. Assume no leakage.-D-1124.A torroidal air-cored coil with 2000 turns has a mean radius of 25 cm, the diameter of each turn being 5 cm. If the current in the coil is 10A. Find (a) the MMF (b) flux and (c) flux density.-M-1125.A mild steel ring having a cross-sectional area of 500mm2 and a mean circumference of 400mm has a coil of 200 turns wound uniformly around it. Calculate (a) reluctance of the ring and (b) the current required to produce a flux of 800µwb in the ring. Assume relative permeability of mild steel to be 380.26.A toroid with a circular cross section of radius 20mm has a mean length of 280mm and a flux ϕ = 1.5mwb. Find the mmf required if for the silicon steel core µr = 1000. Find the mmf required to establish the same flux, if there is an air gap of 1mm thickness of in the core of the toroid.D-10 27. (b) A closed magnetic circuit of cast steel contains 6m long path of cross sectional area 1cm sq and 2cm path of cross- sectional area 0.5 cm2. A coil of 200 turns is wound around the 6 cm length of the circuit and a current of 0.4A flows. Determine the flux density in the 2 cm path, if the relative permeability of the cast steel is 750.28.(b) An iron ring has a cross-sectional area of 400mm2 and a mean diameter of 20 cm. It is wound with 500 turns. If the value of relative permeability is 250, find the total flux set up in the ring. The coil resistance is 480 ohms and the supply voltage is 240 V.29. A coil is wound uniformly with 300 turns over a steel ring of relative permeability 900 having a mean circumference of 40 cm and a cross- sectional area of 5cm2 . If the coil has a resistance of 100 ohms and is connected to a 250 V dc supply, calculate (i) the coil mmf (ii) the magnetic field intensity (iii) total flux (iv) permeance of the ring. –Do-1230.(b) A steel magnetic circuit has a uniform cross sectional area of 4 cm2 and length of 50 cm. A coil of 250 turns is wound uniformly over the magnetic circuit. When the current in the coil is 1.5 A, the total flux is 0.25 mWb. When the current in the coil is 5 A, the total flux is 0.6 mWb. For each value of current, calculate the magnetic field strength and relative permeability of the steel.

31.(b) An iron ring of mean length 30 cm has an air gap of 2 mm and a winding of 200 turns. If the permeability of the iron core is 300 when a current of 1 A flow through the coil, find the flux density. The cross sectional area of the ring specimen is A m232.b) A coil of 800 turns is would on a wooden former and a current 5 A produce a magnetic

flux of 200x 10-6 wb. Calculate the inductance of the coild and induced emf when the current is reversed in 0.2 seconds.33.(b) a coil having an inductance of 60mH is carrying current of 90 A. Calculate the self-induced emf in the coil, when the current is (i) Reduced to zero in 0.03s (ii) Reversed in 0.03s

34.A toroid with a circular cross section of radius 20mm has a mean length of 280mm and a flux ϕ = 1.5mwb. Find the mmf required if for the silicon steel core µr = 1000. Find the mmf required to establish the same flux, if there is an air gap of 1mm thickness of in the core of the toroid.D-1035. Calculate the inductance of a coil of 400 turns wound on an air cored torroidal ring having mean dia of 30cm. The ring has circular cross section of dia 5cm. Also calculate the emf induced in the coil when a current of 4A is reversed in 30ms.-m1336.The number of turns in a coil is 250. When a current of 2 amps flows in this coil the flux in the coil is 0.3 mwb.When this current is reduced to zero in 2 mill seconds the voltage induced in the coil lying in thevicinity of first coil is 63.75 V. Find L1, L2 and M and also N2. Assume coefficient of coupling as 0.75.-D-1137. A coil of 1000 turns is linking a flux of 0.01wb. The flux is reversed in an interval of 0.1 sec. Calculate the average value of the emf induced in the coil. 38 (a) A mild steel ring having a cross-sectional area of 500mm2 and a mean circumference of 400mm has a coil of 200 turns wound uniformly around it. Calculate (a) reluctance of the ring and (b) the current required to produce a flux of 800µwb in the ring. Assume relative permeability of mild steel to be 380.39. A no of turns in a coil is 250. When a current of 20A flows in this coil, the flux in the coil is 0.3 milliwebers. When this current is reduced to zero in 2 milliseconds, the voltage induced in the coil lying in the vicinity of coil is 63.75V. If the co-efficient of coupling between the coil is 0.75 Find (i) Self inductance of the two coils (ii) Mutual inductance (iii) Number of turns in the second coil –D0-11 III A.C.CIRCUITS 11 hrs.Sinusoidal functions - RMS(effective) and Average values- Phasor representation - J operator - sinusoidalexcitation applied to purely resistive , inductive and capacitive circuits - RL , RC and RLC series and parallel circuits - power and power factor - Three phase circuits - Star / Mesh connections - with balanced loads - measurement of power by two wattmeter method.1.A resistance, immersed in oil, has 62.5 resistance and is connected to 500V d.c. supply.

Calculate the power in watts.2.Find the current flowing through 5 resistors

3.What is the impedance of RLC circuit?4.Define RMS value and Average Value./ Define average value and RMS value/ Define average value and RMS value./ Define RMS value

5. A circuit consists of two resistances, R1 and R2, in parallel. The total current passing through the circuit

is IT. Give the equation for the current passing through R1.6.Define Form factor and Peak factor. Define form factor and peak factor7.Write the relationship between the phase and line voltages in the star and delta connected

network.8.What do you understand by a balanced system?9.What are the advantages of polyphase system?10.Write down the expression for power factor in two wattmeter method11.Give the relation between line and phase values of voltage and current in a 3 star and delta

connection.12.Derive the expression for the voltage, current and power in a resistor supplied with a sinusoidal voltage.-M-12

13. Explain about the relation of voltage and current in 3-Ф star and delta connections with necessary phasor

diagramsa.)A balanced star connected load of impedance (15+j 20) per phase is connected to a phase

440 V 50 Hz supply. Find the line currents and power absorbed by the load. Assume RYB phase

sequence.-M-1114.A 3phase, 4 wire 208 V, ABC system supplies a star connected load in which ZA=10∟0,

ZB=15∟30, ZC=10∟-30. Find the line currents, the neutral current and the load power.15.. A 3phase, 4 wire 208 V, ABC system supplies a star connected load in which ZA=10∟0,

ZB=15∟30, ZC=10∟-30. Find the line currents, the neutral current and the load power.-Do-12,D-1116.What is the expression for frequency at resonance RLC series circuit?(a) Derive an expression for the instantaneous current in a purely capacitive circuit, when a

sinusoidal voltage given by e=Emaxsinωt is applied to the circuit. –Do-10/ Derive the expression for the

voltage, current and power in an inductor supplied with a sinusoidal voltage.

17.Draw the phasor when sinusoidal voltage is applied to pure inductance and capacitance18.Explain the behaviour of A.C through (a) pure L (b) R-L series m/1319.If the voltage across a 0.1F capacitor is , find the current flowing in this capacitor in the time domain. Draw the phasor diagram for this circuit.20.A resistance of 50 Ω is connected in series with a pure inductor of 250 mH. The circuit is connected to a 50 Hz supply. The voltage across the resistance is 150 V. Calculate the supply voltage.21.A series circuit has R=10 , L=50 mH and C=100F and is supplied with 200 V, 50Hz. Find (a) impedance, (b) current, (c) power (d) Power factor and voltage difference across each element.-

M-1122. A series RC circuit takes a power of 5 KW when connected to 230V 50Hz supply. The voltage across the resistor is 130 V. Calculate the resistance, capacitance, current, power factor and impedance.23.A coil of resistance 10 ohms and inductance 0.1H is connected in series with a capacitor of

150 F across 200V, 50Hz supply. Calculate (a) Inductive reactance, Capacitive reactance,

impedance, current, and power factor and (b) the voltage across the coil and capacitor respectively.

24. A series RLC circuit has R=25 ohms, L = 0.221 H and C = 66.3F and is supplied at 150 volts 60c/s Find

(i) the equivalent impedance (ii) the power factor and (iii) the reactive power.

25.A circuit is having resistance R in series with a capacitor C. An ac voltage is applied to this circuit. Derive equations for voltage, current, impedance and power factor. Draw the phasor diagram.

26.A coil of resistance 10 and inductance of 0.1 H is connected in series with a 150 F capacitor across 200V, 50Hz supply. Calculate

(i) inductive reactance, capacitive reactance, impedance, current and power factor.

(ii) the voltage across the coil and capacitor respectively.

27.A coil of inductance 0.12 H and resistance 3 kΩ is connected in parallel with a 0.02 µF capacitor and is

supplied at 40 V at a frequency of 5 kHz. Determine (a) the current in the coil, and (b) the current in the

capacitor. (c) Draw to scale the phasor diagram and measure the supply current and its phase angle; check

the answer by calculation. Determine (d) the circuit impedance and (e) the power consumed.28.A coil of resistance 25 Ω, and inductance 0.159 H is in parallel with a circuit having 60 Ω

resistor and 125 μF capacitor. This parallel circuit is connected to a 230 V, 50 Hz supply. Calculate the supply

current, the equivalent circuit impedance and reactance.29.A coil of resistance 10 ohms and inductance 0.1H is connected in series with a capacitor of

150 µF across 200V, 50Hz supply. Calculate (a) Inductive reactance, Capacitive reactance, impedance,

current, and power factor and (b) the voltage across the coil and capacitor respectively.-D-1030.. (b) Acapacitor of 100µF is connected across a 200V, 50Hz single phase supply. Calculate (i) the reactance of the capacitor (ii) rms value of current and (iii) the maximum current31.A coil of 10 ohms and inductance of 0.1H in series with a 150µF capacitor across

200V,250HZ supply. Calculate (i) inductive reactance, capacitive reactance and impedance of the circuit (ii) current

(iii) power factor (iv) voltage across the coil and capacitor respectively

32.A resistance of 20Ω and an inductance of 0.2H and a capacitance of 100µF are connected in series 220V,

50Hz main. Determine (a) impedance (b) Current taken from mains (c) Power and power factor of the circuit.

(or)Mo-11

33.A coil of 10 ohms and inductance of 0.1H in series with a 150µF capacitor across 200V,250HZ supply.

Calculate (i) inductive reactance, capacitive reactance and impedance of the circuit (ii) current (iii) power

factor (iv) voltage across the coil and capacitor respectively.-Do-12

34.Explain with neat figures the power measurement in three phase circuits using two-wattmeter method.Do-11

Explain in detail about measurement of three phase power by two wattmeter method.-Mo-11Describe the three phase power measurement by two watt meter method for balanced load.M-

10Draw and explain the measurement of 3 phase power by two wattmeter method.D-10Explain with help of calculation and diagram how three-phase power in A.C. circuit can be

measured by the two-wattmeter method.-Do-10Prove that the three phase power can be measured using two single-phase wattmeter.-m13Explain in detail about the measurement of power by two Wattmeter method.M-12Explain with help of calculation and diagram how three-phase power in A.C. circuit can be

measured by the two-wattmeter method.Draw and explain the measurement of 3 phase power by two wattmeter method=m-08A three phase load consumes power of 12kW at 0.9 power factor. If two wattmeter method is

applied to measure the power, what are the individual readings of the wattmeters?D-11

TEXT/REFERENCE BOOKS:1. Mittle.B.N, Aravind Mittle, "Basic Electrical Engineering" , Tata McGraw Hill", 2nd Edition. Sep 20052. Theraja.B.L, "Fundamentals of Electrical Engineering and Electronics", S.Chand & Co., 1st Multicolor Edition, 2006 (Reprint 2009)3. Smarajit Ghosh, "Fundamentals of Electrical and Electronics Engineering", PHI Learning Private Ltd, 2nd Edition, 2010.4. Wadhwa.C.L, "Basic Electrical Engineering", New Age International, 4th Edition, 2007. (Reprint June 2010)5. Abhijit Chakrabarti, Sudipta nath & Chandan Kumar Chanda, "Basic Electrical Engineering", Tata McGraw Hill, 1st Edition, 2009.6. T. Thyagarajan, “Fundamentals of Electrical Engineering”, SciTech Publications, 5th Edition, Reprint Jan 2010BASIC ELECTRONICS ENGINEERINGUNIT I SEMICONDUCTOR DEVICES AND LOGIC GATES 10 hrs.Discrete devices - PN junction diodes - Zener diodes - Tunnel diodes- Thermistors - Bipolar junction transistors - Field effect transistors (FET and MOSFET) - Uni junction transistors - Silicon controlled rectifiers and Triacs. Universal Gates - Half Adder - Full Adder.1.How an avalanche breakdown occurs?2.Give the equation for the intrinsic stand-off ratio.3.Draw the symbol and characteristics of Zener diode.4.What are called Universal Gates and draw its symbols?5.List the applications of Zener diode.6.What is meant by firing and commutation of thyristor?7.List the applications of Zener diode.8. Draw a half adder with its truth table.9.Discuss in detail about the different types of logic Gates.m-1210.Explain the V-I characteristics of a PN junction diode and Zener diode.-D-11

11.With a neat sketch and its characteristics explain the theory and operation of PN junction diode.m-12

12.Explain the operation of bipolar junction transistor with a neat sketch.-M-11, m/1313.Explain the VI characteristics of a TRIAC-M-1114. Write short notes on: (a) SCR and (b) TRIAC.m/13, .-D-11

UNIT II RECTIFIERS, AMPLIFIERS AND OSCILLATORS 10 hrs.Half and full wave rectifiers- Capacitive and inductive filters- ripple factor- PIV-rectification efficiency. CB, CEand CC Configuration - RC coupled amplifier- positive and negative feedback - Barkhausen criterion for oscillations -RC and LC oscillators.1.Compare bridge rectifier with the center-tapped rectifier.2.Mention the conditions for oscillation.3.Define Ripple factor.4.Define oscillator.5.Define ripple factor.6.State Barkhausen criterion.7. Differentiate rectifiers and filters.8.Derive the expression for average value, rms value, efficiency and PIV for half-wave

rectifier.M-118(a).Derive an expression for the Average value and the RMS value of a half wave rectifier

circuit.-D-119.Draw the circuit diagram of a half wave and full wave rectifies and explain its operation.-m-1210.Explain the internal and external characteristics of common emitter configuration of a

transistor.-D-1111.Explain the input and output characteristics of transistors in CC configuration.-m-1212.. Explain the internal and external characteristics of common emitter configuration of a transistor.m/1313. How is a sine wave produced in a RC phase shift oscillator?m/1314.How sine wave is produced in a RC phase shift oscillator?M-1115.Describe the operation of RC and LC oscillators.-D-1116.Calculate (i) form factor and (ii) peak factor of a full wave rectified sine waveTEXT / REFERENCE BOOKS:1. Sedha.R.S, A Text book of Applied electronics, 2nd Edition, S.Chand & company, 2005.2. Dr.Bhattacharya.S.K and Dr.Renu vig, Principles of electronics, 3rd Edition, S.K.Kararia & Sons, 2002.