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1 BSCO8,BSE8,BSET8 BTCSE22,BTEE22,BTETE22 IV SEMESTER B.TECH EXAMINATION, JANUARY-2013 ANALOG ELECTRONIC CIRCUITS Time: 3 Hours Max. Marks: 75 GROUP A : Answer any three questions. (Question No. 1 is compulsory) Q.1 What do you understand by transistor biasing? (05) Q.2 Explain voltage divider Bias & source Bias. (10) Q.3 Explain FET as an amplifier & voltage gain of a FET amplifier. (10) Q.4 Explain all three parameters of FET (a) Ac drain resistance (b) Transconductance (c) Amplification (10) Q.5 Explain static characteristics of FET & define pinch off voltage & gate source cut off voltage. (10) GROUP B : Answer any three questions. (Question No. 6 is compulsory) Q.6 Write not on thermal stability. (05) Q.7 Comparison between BJI and FET (10) Q.8 Draw and explain D.C and A.C equivalent circuits of an amplifier. (10) Q.9 Mention and explain different distributors in amplifiers. (10) Q.10 Explain a diode as H.W rectifier. Give circuit, operation and the waveform. (10) GROUP C: All Questions are Compulsory. Q.11 Fill in the blanks (each question carries 2 marks) In a transistor, the emitter diode is biased and collector diode is biased. (ii) The current gain is maximum only in configuration. (iii) The Q point is given by the of DC and AC load lines. (iv) For a transistor, the typical value of hfe in CE circuit is (v) The SCR is made of germanium Q.12 Multiple choice question. (Each question carries 2 marks) hie is given as (a) (c) V I V I BE B B BE I constat V C CE cons tan t (b) IB VVB VBEconstan t I (d) V C c I cons tan t B

2 (ii) (iii) (iv) (v) I/p characteristics curve of CE amplifier is between (a) VBE Vs VCE (b) VCE Vs IB (c) VCE Vs IE (d) IB Vs VBE Maximum Efficiency of Half Wave Rectifier is (a) 40.6% (b) 81.2% (c) 20.3% (d) 50% An SCR is a (a) Current triggered device. (b)voltage triggered device (c) Power triggered device (d) None of these A diac is equivalent to (a) Two diodes connected in parallel. (b) Two diodes connected in series. (c) Two four layers diodes connected in reverse parallel. (d) Two transistors connected in parallel. Q.13 True or false (each question carries 1 mark). A Common Collector amplifier is generally used for impedance matching. (ii) The impedance of the loudspeakers is normally between 24 and 64 ohms. (iii) Reverse biasing of a PN diode decreases its junction depletion layer. (iv) The slope of the AC load line is greater than that of the DC load line. (v) The diacs are generally used to trigger the SCRs. ******

3 BTCSE27, BTEE27, BTETE27 IV SEMESTER B.TECH EXAMINATION, JANUARY ELECTRONIC DEVICES & CIRCUIT Time: 3 Hours Max. Marks: 75 GROUP A : Answer any three questions. (Question No. 1 is compulsory) Q.1 Distinguish between voltage amplifier & power amplifier. (05) Q.2 What do you mean by feed-back? What do you understand by negative & positive feed-back? Why negative feed-back applied is high gain amplifiers? (10) Q.3 Draw an emitter follower & explain its working? Why it is called emitter follower? Where does this amplifier find its use? (10) Q.4 Draw & discuss in detail the circuit of an RC-phase shift oscillator. (10) Q.5 Draw the circuit of a wein bridge oscillator & explain its working. Why negative feedback employed in this oscillator circuit in addition to the usual positive feed back? (10) GROUP B : Answer any three questions. (Question No. 6 is compulsory) Q.6 What is meant by virtual ground? (05) Q.7 With the help of suitable diagram explain the working principle of bistable multivibrator. (10) Q.8 Draw the circuit of class C transformer coupled tuned amplifier using one transistor and describe its working. (10) Q.9 Draw the circuit and explain a crystal oscillator. (10) Q.10 Discuss the effect of negative feedback on voltage gain, stability, distortion, bandwidth, output and input impedance of an amplifier and write the advantages of negative feedback amplifiers. (10) GROUP C: All Questions are Compulsory. Q.11 Fill in the blanks (each question carries 2 marks) An R-C coupling is used for amplification and very small frequency signals are amplified by using coupling. (ii) The last stage of an audio amplifier is called and is used to cool down power transistors. (iii) The gain of an amplifier with feedback is also called a loop gain; emitter follower is used for. (iv) For oscillations to start, the loop gain Am of the oscillator must be more than initially. (v) For an OP-amp the input impedance is and the output impedance is. Q.12 Multiple choice question. (Each question carries 2 marks) CMRR is defined as (a) Ad/Acm (b) Acm/ Ad (c)ad (d) Acm

4 (ii) The Curve drawn between voltage gain and frequency of an amplifier is known as (a) bandwidth (b) frequency response (c) Cut off frequency (d) decibel (iii) A push pull amplifier (a)reduces odd harmonics in the output (b)reduces even harmonics in the output (c)is the first stage of an audio amplifier (d)uses a single transistor (iv) An oscillator is a (a) rotating device (b) Static electronic device (c) rotating (d)electronic device (e) electro mechanical device (v) An op amplifier is a device having the following number of input terminals (a) one (b) two (c) three (d) four Q.13 True or false (each question carries 1 mark). (ii) (iii) (iv) (v) An oscillator employs positive feedback. An op-amp has four input terminals. A switch can have two states. Heat sinks are used to increase the gain of the transistor. The lower or upper cut off frequency is also known as 3 db frequency. ******

5 BTEE29,BTETE29 IV SEMESTER B.TECH EXAMINATION, JANUARY-2013 ELECTRICAL MEASUREMENT - I Time: 3 Hours Max. Marks: 75 GROUP A : Answer any three questions. (Question No. 1 is compulsory) Q.1 Describe the basic principle of operation of a dc potentiometer. (05) Q.2 Explain the term Standardization of a potentiometer. Describe the procedure of standardization of a D.C. potentiometer. (10) Q.3 Derive the general equation for balance for an AC bridge (10) Q.4 Derive the equation of balance for an Andersons bridge. How the phasor diagram fir condition s under balance? (10) Q.5 Explain principle of operation of thermo electric instrument. (10) GROUP B : Answer any three questions. (Question No. 6 is compulsory) Q.6 Write short notes on Strain Gauges & measurement of strain. (10) Q.7 Explain the crompton potentiometer circuit. Also explain its uses for the calibration of voltmeter and ammeter? (10) Q.8 A resistance of approximate value of 80 is to be measured (10) By voltmeter ammeter method using a 1 A ammeter having a resistance of 2 and a 50 V voltmeter having a resistance of a) Suggest which one of the two methods should be used? b) Supposing in the suggested method the following measurements are made. I= 0.42 A and V= 35.5 V What is the resulting error if the accuracy of the instruments is + 0.5% at full scale and the errors are standard deviations. Q.9 Derive the equations of balance for an Anderson s bridge. (10) Draw the phasor diagram for conditions under balance. Q.10 The inductance of 25 A electrodynamo meter ammeter is controlled by a spring having a constant of Nm/degree. The full-scale deflection is Determine the inductance of instrument measuring a current of 10A. The mutual inductance 0 0 deflection is 2 micro H. (10) GROUP C: All Questions are Compulsory. Q.11 Fill in the blanks (each question carries 2 marks) (ii) (iii) (iv) (v) Units of amount of substance. Kelvin s bridge is used for the measurement of resistance. De Sauty s bridge is used for the measurement of. Rectifier is used to convert to. material is used for shunts of DC instruments

6 Q.12 Multiple choice question. (Each question carries 2 marks) (ii) (iii) (iv) (v) In ionization types of vaccum gauges, the pressure (p) is (a) P I G / I P (b) P I P / I G (c) P I K /I G (d) P I P /IK A potentiometer is basically a (a) deflectional type instrument (b) null type instrument (c) deflectional as well as null type (d) digital instrument Sensitivity of moving magnet type transducer is stated in a) v / mm-s b) mv / mm-s c) v / m-s d) none of these Transformation ratio is (a) secondary power / primary power(b) primary phasor / secondary phasor c) primary power / secondary powerd) secondary phasor / primary phasor The unit of solid angle is (a) radians (b) hentry (c) Kelvin (d) none of these Q.13 True or false (each question carries 1 mark). PMMC instruments are used for DC measurements only. (ii) Multi-range ammeters are used for ranges of meters from (1 to 5) A. (iii) Unit of plane angle is steradian. (iv) Wein s bridge is used for the measurement of capacitance. (v) Thermo couples are used for measurement of pressure. ******

7 BTETE28 IV SEMESTER B.TECH EXAMINATION, JANUARY-2013 ELECTROMAGNETIC ENGINEERING Time: 3 Hours Max. Marks: 75 GROUP A : Answer any three questions. (Question No. 1 is compulsory) Q.1 Write a notes on energy, stored in magnetic field (05) Q.2 In certain region the current density vector is 1 = 3x I x + (y-3) I Y + (2+z) I z A/m 2 find total current flowing out of surface of box bounded by five planes x = 0, y = 0, y = z, z = 0 & 3x + 2 = 3. (10) Q.3 i) Determine energy stored in electric field in a concentric spherical cal shell, ii) A flat slab of dielectric ( r = 5) is placed normal to a uniform field of flux density 1 c/m 2 slab occupies a volume of 0.1/m 2 and is uniformly polarizedfind polarization in slab, total dipole moment at slab. (10) Q.4 i) State & explain Ampere circuital law. ii) Prove that inductance of coaxial cable L= μ/2π {log (D/d)} (10) Q.5 State & explain biot savarts law, Determine flux density produced at any point p in our distant R from on infinite linear conductor carrying current I (10) GROUP B : Answer any three questions. (Question No. 6 is compulsory) Q.6 What is divergence theorem? (05) Q.7 Find the unit normal to the surface x 2 y + 2xz = 4 at the point (2,-2,3). (10) Q.8 Draw a diagram to show increamental area element in cylindrical co-ordinates normal to a) r b) c) z. (10) Q.9 Explain the Equipotential surface. (10) Q.10 Explain non-conservative field EMF. (10) GROUP C: All Questions are Compulsory. Q.11 Fill in the blanks (each question carries 2 marks) The unit of electric field intensity is. (ii) The unit of surface charge density is expressed as. (iii) A vector is a quantity, which have both &. (iv) The divergence of a vector field A is expressed as. (v) The vector field A is irrotational if A is.

8 Q.12 Multiple choice question. (Each question carries 2 marks) (ii) (iii) (iv) (v) The cross product of two vectors A and B is given by (a)a.b cos (b) A B sin (c) A B sin 1n (d) None of these. The gradient of a scalar field A can be expressed as (a) A (b). A (c) A damping torque (d) none of these If a vector field A is solenoidal then it will possesses the following relations (a) A = 0 (b). A = 0 (c) 2 A = 0 (d) A The rate of change of potential with distance in direction of electric force is expressed as (a) Volt-m (b) Volt/m (c) C /m (d) N / M The unit of magnetic flux density is (a) weber (b) weber / m (c) Tessa (d) Unitless quantity Q.13 True or false (each question carries 1 mark). The unit of relative permittivity is farad / metre. (ii) The total flux emerging from a closed surface is equal to the total charge enclosed by the surface is stated by coulomb s law. (iii) A scaler quantity has only the magnitude. (iv) The dot product of two vectors A and B is defined as A.B sin (v) The curl of vector field A is expressed as A. ******

9 BTETE31P-I IV SEMESTER B TECH IN ELECTRONIC AND TELECOMMUNICATION ENGINEERING EXAMINATION JANUARY-2013 ANALOG ELECTRONIC CIRCUITS Time: 1 hours (5X5=25) I. ANSWER ALL QUESTIONS. 1. What do you understand by transistor biasing? What is the need of it? 2. What do you mean by forward and reverse biasing? 3. Explain construction and working of n- channel FET. 4. Mention and explain different distortion in amplifiers. 5. Explain the operation of LC filter.

10 BTETE32P-II IV SEMESTER B TECH IN ELECTRONIC AND TELECOMMUNICATION ENGINEERING EXAMINATION JANUARY-2013 ELECTRICAL MEASUREMENT Time: 1 hours (5X5=25) I. ANSWER ALL QUESTIONS. 1. Describe international standards of Mass and Length. 2. Define the term Units, Absolute Units, Fundamental Units, and Derived Units With suitable examples to support your answer. 3. Define the SEVEN basic units of SI system. 4. Describe the working of Wheatstone bridge and derive the condition of balance. 5. Describe the substitution method of measurement of medium resistance. List the factor on which the accuracy of the method depends.

11 Fourth Semester B. Tech (CS), Examination Dec/Jan BSC06 Society, Environment & Engineering Time:-3Hours Max. Marks: - 75 SECTION-A Attempt any five Questions. (5*5) 1. What is the significance of sociology in modern society? 2. What is community? 3. Define Socialization. 4. What is social change? 5. What is social control? 6. Define the term Civilization? 7. What is communism or Marxism? SECTION-B Attempt any two Questions. (10*2) 8. What is technological forecasting and up gradation? 9. Define optimization. Discuss its basic concepts. 10. What are the main sources of air pollution? Discuss each in brief? SECTION-C Attempt any two Questions. (15*2) 11. What is man power planning? Describe the need for man power planning? 12. What are the different types of trainings in the industry? 13. Write short note on- (1) Motivation (2) Communication

DHANALAKSHMI COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING EC6202 ELECTRONIC DEVICES AND CIRCUITS

DHANALAKSHMI COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING EC6202 ELECTRONIC DEVICES AND CIRCUITS UNIT-I - PN DIODEAND ITSAPPLICATIONS 1. What is depletion region in PN junction?