Unit-1(2 Marks and 16 Marks)

7/29/2019 Unit-1(2 Marks and 16 Marks)

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E1153BASIC ELECTRICAL & ELECTRONICS ENGINEERING

SACET, SIRUGANOOR

QUESTION BANK

SUBJECT CODE & NAME : EE1153 BASIC ELECTRICAL &

ELECTRONICS ENGINEERING

YEAR / SEM : I / II

UNITI

ELECTRIC CIRCUITS AND MEASUREMENTS

PARTA (2 MARKS)

1. State Ohms law and its limitations.2. State Kirchhoffs voltage and current law.3. Derive the equation for equivalent resistance of number of resistors

connected in parallel.

4. What is meant by electric energy?5. Distinguish between power and energy.6. What are lumped circuits?7. What is meant by electric power? Give different forms of expression for

electric power.

8. Draw power triangle.9. Define time period and frequency of an alternating quantity.10.Explain the terms (a) instantaneous value and (b) average value for an ac

signal.

11.Draw sinusoidal, saw tooth and half- rectified sinusoidal waveforms.12.Define form factor and peak factor.13.Define time period and frequency.14.Define RMS value


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15.Define power factor and power in A.C circuit.16.Give the advantages of phase system.17.Distinguish between power and true power.18.Distinguish between apparent power and true power.19.Mention the 2 types of wattmeter.20.Mention the 2 types of Moving iron instruments.21.Why cannot a moving coil instrument be used in AC circuits?22.State the principle of moving iron instrument.23.Name the coils in the wattmeter.24.What are the advantages and disadvantages of MI instruments?25.List out the measuring instruments you know.26.How an ammeter and voltmeter are connected in a circuit? Why?

PARTB

1. (i) Derive an expression for RMs value of an A.C supply.(8)(ii) A coil of resistance 100 and inductive reactance 200 is connected

across a supply voltage of 230V. Find the supply current.(8)

2. (i) Explain the working principle of moving iron instruments.(12)(ii) Why the PMMC instruments are not used for A.C. measurements.(4)

3. What is the three phase circuit? The load in each branch of star connectedthree phase circuit consist of 10 resistance and 0.06 H inductance in

series. The line voltage is 430V. Calculate the phase voltage and the

phase current.(8)

4. (i) Explain the working of a Dynamometer type watt meter with neatdiagram. (12)

(ii) Why the PMMC instruments are not used for A.C. measurements.(4)


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5. A circuit is composed of a resistance 6 and a series capacitivereactance of 8 . A voltage e(t)=141 sin 314t is supplied to the circuit.

Find (i) Complex impedance, (ii) Effective value of current, (iii) Power

delivered to the circuit, (iv) Capacitance of the capacitor.

6. A series RLC circuit is connected to a 230V, 50hz, 1-phase AC supply.The value of R=5, L=13mH and C=140F. Find total reactance,

impedance, current drawn by the circuit and p.f of the circuit.

7. A resistance of 20 and an inductance of 0.2H and a capacitance of 100F are connected in series across 220V,50 Hz main. Determine (i)

Impedance (ii) current taken from mains, (iii) Power and power factor of

the circuit.

8. A coil of resistance 10 and inductance 0.1 H is connected in series witha 150 F capacitor across 200V,50 Hz supply. Calculate (i) Inductive

reactance, Capacitance reactance, impedance, current and power factor.

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

9. A series circuit having pure resistance of 40 , pure inductance of 50mHand a capacitor is connected across a 400V, 50 Hz ac supply. This LC

circuit draws a current of 10A. Calculate 1) Power factor of the circuit, 2)

Capacitor value.

10.Three 100 resistors are connected first in star and then in delta across415 V, 3-phase supply. Calculate the line and phase currents in each case

and also the power taken from the source.

11.Explain the working principle of induction type energy meter.(12)12.Explain the construction and working principle of Dynamometer types

wattmeters.(12)

13.(i) Explain the construction and working principle of moving coilinstruments.


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(ii)State and explain Kirchoffs law. (8)

14.(ii)Explain the working of a Dynamometer wattmeter with a neat sketch.(8)

15.Define the following (16)(i) RMS Value(ii) Average Value(iii) Instantaneous Value(iv) Real power(v) Apparent power(vi) Reactive power(vii) Frequency(viii) Balanced three phase circuit

16.Name the instrument used for measuring the electrical power consumedduring a specific period. Discuss its principle of operation with suitable

diagram. (16)

17.(i) A series circuit has R=10, L=50mH, and C=100F and is suppliedwith 200V, 50Hz. Find (i) Impedance (ii) current (iii) power (iv) power

factor (v) voltage drop across the each element. (8)

(ii)Derive the equation for equivalent resistance of number of resistors

connected in parallel. (8)

18.Illustrate with a neat diagram, the construction and operation of apermanent magnet moving coil. How could it be modified for use as (i)

ammeter (ii) voltmeter (16)

19.A 400V is applied to three star connected identical impedances eachconsisting of a 40 resistance in series with 3 inductance reactance.

Find (i) line current (ii) Total power supplied.


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20.Find the current through each branch by network reduction technique.(16)

21.Calculate a) the equivalent resistances across the terminals of the supply,b) total current supplied by the source and c) power delivered to 16 ohm

resistor in the circuit shown in figure. (16)

22.In the circuit shown, determine the current through the 2 ohm resistorand the total current delivered by the battery. Use Kirchhoffs laws. (16)


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23.(i) Determine the current through 800 ohm resistor in the network shownin figure. (8)

(ii) Find the power dissipated in 10 ohm resistor for the circuit shown in

figure. (8)


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24.(i) In the network shown below, find the current delivered by the battery.(10)

(ii) Discuss about voltage and current division principles. (6)

25.Find the current through branch a-b using mesh analysis shown in figurebelow. (8)


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26.Find the nodal voltages in the circuit of figure. (16)

27.Using Mesh analysis, find current through 4 ohm resistor. (16)


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28.Find the resistance between A & B , A & C

Documents

Unit-1(2 Marks and 16 Marks)