B.Tech II SEM Question Bank. Electronics & Electrical Engg UNIT-1

Transcription

1 UNIT-1 1. State & Explain Superposition theorem & Thevinin theorem with example? 2. Calculate the current in the 400Ωm resistor of below figure by Superposition theorem. 3. State & Explain node voltage theorem? Illustrate the application of the theorem with reference to an appropriate electric circuit? 4. Find voltage across 20Ωregistor as given in figure using nodal & mesh method? 5. Using Thevinin s theorem. Find the current in 11.25Ω Resistor?

2 6. State & Explain Kirchhoff law? & Compute the power dissipated in the 12Ω Resistor by Superposition theorem? 7. Using source conversion techniques find V 0 b/w A & B? 8. Using loop current methods find the current I 1 & I 2? 9. What is the current through Switch S when it is closed?

3 10. Find the voltage V AB? 11. Find the voltage of a single Resistance to replace the network b/w the terminals? UNIT-2 1. For a single phase sinusoidal waveform.find the average & RMS value of max value.determine the form factor of sine wave? 2. In a series RC circuit the Value of R=10 Ω C= 25 nanofarad.a sinusoidal Voltage of 50 Ω MHZ is applied & Max Voltage across the capacitance is 2.5 volt. Find the max Voltage across the Series Combination? 3. A 50HZ sinusoidal Voltage=311sin wt is applied to RL Series ckt if the magnitude of Resistance is 50 Ω and that of of inductance 0.02 henry Calculate the effective value of Steady state Current & relative Phase angle? Obtain Expression for instantaneous current? 4. An alternating voltage c=200 sin314 is applied to a device which offers an ohmite resistance of 20 Ω to the flow of current in one direction While preventing the flow of current in opp. Direction Calculate average & RMS value & form factor over one cycle? 5. A single phase 50Hz motor takes 10A current at 0.8 power factor lagging form a 240V supply Calculate The active & reactive Component of the ckt The power taken from the supply

4 The o/p of the motor if the efficiency of the motor is 85% 6. How power can be measured using two wattmeter method for balanced & unbalanced load. Derive an expression? 7. Derive the frequency Response or curve of a series RLC Ckt & Discuss the effect of varying the freq over wide range upon the ckt parameter R, X L,X C,Z,I& power factor? 8. Proove the resonance frequency for the given ckt F=1/2π (1/LC-R 2 /L 2 ) 9. A100V, 80W Lamp is to be operate on 230V, 50HZ.Calculate the pure inductance to be connected in series with the lamp so that lamp may ran on its correct voltage if the power factor of the lamp is to be improved to unity Calculate the value of capacitor which is connected across the ckt. UNIT III Q.1. For a single phase transformer desire the expression for EMF equation. Q.2. Explain different types of torque present in induction type of measuring instrument. Q.3. describe the essential parts of DC machine regarding the construction. Also describe the principle of operation. Q.4. A 250 volt DC shunt motor takes #0 A current while running at full load. The resistance of motor armature and field winding are 0.1V and 200 ohm respectively. Q.5. Draw and explain phasor diagram of an ideal transform a no load and on load. Q.6. desire the equation of emf induce & in the winding transformer. Q.7. define the voltage regulation of a transformer and deduce the expression for voltage regulation. Q.8. explain the application of DC generator and DC motor.

5 Q.9. An ideal transformer having 90 turn on the primary and 2250 turn on secondary is connected to 200V, 60 Hz supply. The load a cross the secondary. Draw a current of 2A of power factor of.8 logging calculate:- (a) The value of the primary current (b) The peak value of flux link with secondary and the draw the phasor diagram. UNIT IV Q.1. compare the various transistor connections in terms of input and output resistance and voltage gain. Which connection is most common and why? Q.2. a transistor is connected in (CE) config. In which collector supply is 8v. & the voltage drop across the resistance RC connected in the collector circuit is 0.5v. The value of RC=800 ohm if α =.96 Determine 1. CE voltage 2. Base current Q.3. describe the method to turn ON OFF the bi directional thyristors. Give the details of their application. Q.4. Describe the equivalent circuit and characteristic of uni-junction transistor (UJT TRIAC) Q.5. explain early effect with suitable plots of potential and minority concentration throughout the base region. Q.6. Discuss the two possible source of breakdown in a transistor as the collector to emitter voltage increased. Q.7. explain how a transistor can be used as an apply of compare CE, CB, CE all parameter. Q.8. explain why a transistor can not be achieved by connecting to back to back diode. In a transistor explain why emitter region is heavily doped, base width is small and collector area is large. Q.9. draw the voltage characteristic of SCR and explain its behavior using two transistor analog and hence suggest various Trigg modes on SCR. UNIT V Q.1. Describe the basic principle of modulation and what its need, present the mathematical analyzing of amplitude modulated wave. Q.2. Describe the optical communication covering the modulation photo detector and optical fiber etc. Q.3. Give the block diagram of a super heterodyne receiver and explain the function of each component.

6 Q.4. If the max peak to peak voltage of and amplitude is a and spread between minimum points is B; show that modulation factor is given by:- (A-B)/ (A+B) Q.5. what do you understand by detection? Draw the circuit diagram of a diode detector and Explain its working? Q.6. draw the satellite communication system using a diagram. Q.7. Merit and Demerits of FM over AM. Q.8. Short note on:- (a) TV (b) Multiplexing Q.9. Explain AM modulation and Demodulation with related waveform and find modulation index for AM.