Pulse & Digital Circuits B.Tech Question Paper : vardhaman.org

College : Vardhaman College Of Engineering
Degree : B.Tech
Department : Electronics & Communication Engineering
Semester : IV
Subject : Pulse & Digital Circuits
Document type : Question Paper
Website : vardhaman.org

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Vardhaman Pulse & Digital Circuits Question Paper

Four Year B. Tech IV Semester Regular/Supplementary Examinations
(Electronics and Communication Engineering)
Date : 4 June, 2014
Time: 3 hours
Max Marks: 75
Answer ONE question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only

Related : Vardhaman College Of Engineering Aerospace Vehicle Structures-I B.Tech Question Paper : www.pdfquestion.in/6345.html

June – 2014

Unit – I
1. a) With relevant waveforms, explain the response of an RC Low pass circuit
b) For the attenuator circuit shown in the Fig.1,calculate and plot output for the cases :i. C1 = 50pF ii. C1 = 150pF
2. a) With relevant wave forms, explain the response of an RL High pass
b) In a low pass RC circuit, R=2KO, C=1µF. If a 2ms pulse with 5V amplitude

Unit – II
3. a) With the help of a neat circuit diagram and transfer characteristics explain the working of a two level clipper.
b) In the negative clamper circuit Rs=Rf =100 – , R=10K- and C=1.0- F. At t=0 Draw the output waveform.
4. a) Explain working of a transistor as a switch, indicating base current
b) The input voltage Vi applied to a two level clipper shown

Unit – III
5. Design a self biased bistable multivibrator for the following specifications :
6. a) Design an astable multivibrator to produce an unsymmetrical square
b) With neat circuit diagram and relevant wave forms explain fixed bias transistor bistable multivibrator.

Unit – IV
7. a) Explain the working of a transistor Bootstrap time base generator
b) With the help of a circuit diagram and waveforms explain the frequency division by an astable multivibrator.
8. a) With a neat circuit diagram and necessary waveforms explain the working of a transistor current time base generator.
b) Explain the working of monostable relaxation circuits as dividers.

Unit – V
9. a) Compare the unidirectional and bidirectional sampling gates. 7M
b) Draw a TTL NAND gate and explain its operation. 8M
10. a) Verify the truth table of RTL NOR gate with circuit diagram of two
b) For the four diode gate RL = RC = 100KO and that R2=2KO, Rf = 50O
gain A, Vmin and Vc(min). Compute Vn(min) for V = Vmin.

May – 2014

Regulations: VCE-R11
Pulse And Digital Circuits :
(Electronics and Communication Engineering)
Date: 4 June, 2014
Time: 3 hours
Max Marks: 75
Answer ONE question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only

Unit – I :
1. a) With relevant waveforms, explain the response of an RC Low pass circuit with a square wave input under different time constants. 7M
b) For the attenuator circuit shown in the Fig.1, calculate and plot output for the cases:
i. C1 = 50pF
ii. C1 = 150pF 8M
The input ( ) i V t is a step of 10V and C2=100pF. 8M

2. a) With relevant wave forms, explain the response of an RL High pass circuit for a pulse input voltage. 7M
b) In a low pass RC circuit, R=2KO, C=1µF. If a 2ms pulse with 5V amplitude is applied as input to this circuit, sketch the output wave form. 8M

Unit – II :
3. a) With the help of a neat circuit diagram and transfer characteristics explain the working of a two level clipper. 7M
b) In the negative clamper circuit Rs=Rf =100 ?, R=10K? and C=1.0?F. At t=0 a symmetrical square wave signal of amplitude 10 V and frequency 5 KHz is applied. The input signal extends from 0 to 10 V. Draw the output waveform. 8M
4. a) Explain working of a transistor as a switch, indicating base current requirement and junction voltages of silicon npn transistor at room temperature. 7M
b) The input voltage Vi applied to a two level clipper shown in Fig.2 varies linearly from 0 to 150V. Sketch the output voltage V0 to the same time scale as the input voltage. Assume ideal diodes. 8M

Unit – III :
5. Design a self biased bistable multivibrator for the following specifications: Vcc=18V, (hfe)min=20, Ic(sat)=20mA, R1=R2, IB(on)=2 (IB)min and VBE (cut-off)= -1V. Neglect junction voltages and ICBO. Assume npn silicon transistors. 15M
6. a) Design an astable multivibrator to produce an unsymmetrical square wave of TA=0.5m sec and TB=0.4m sec. The square wave amplitude is 15V. Assume (hFE)min=20; (Ic) sat=5ma and (VCE)sat =0. 8M
b) With neat circuit diagram and relevant wave forms explain fixed bias transistor bistable multivibrator. 7M

Unit – IV :
7. a) Explain the working of a transistor Bootstrap time base generator With a neat circuit diagram and necessary waveforms.7M
b) With the help of a circuit diagram and waveforms explain the frequency division by an astable multivibrator.8M
8. a) With a neat circuit diagram and necessary waveforms explain the working of a transistor current time base generator. 7M
b) Explain the working of monostable relaxation circuits as dividers. 8M

Unit – V :
9. a) Compare the unidirectional and bidirectional sampling gates. 7M
b) Draw a TTL NAND gate and explain its operation. 8M
10. a) Verify the truth table of RTL NOR gate with circuit diagram of two inputs. 8M
b) For the four diode gate RL = RC = 100KO and that R2=2KO, Rf = 50O. For Vs = 25V, compute gain A, Vmin and Vc(min). Compute Vn(min) for V = Vmin. 7M