Download PHE-10 - IGNOU

PHE-10
ASSIGNMENT BOOKLET
Bachelor's Degree Programme (B.Sc.)
Electrical Circuits and Electronics
(Valid until June 30, 2008)
School of Sciences
Indira Gandhi National Open University
Maidan Garhi, New Delhi-110068
2007-08
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Dear Student,
We hope you are familiar with the system of evaluation to be followed for the Bachelor’s Degree
Programme. At this stage you may probably like to re-read the section on assignments in the Programme
Guide for Elective Courses that we sent you after your enrolment. A weightage of 30 per cent, as you are
aware, has been earmarked for continuous evaluation which would consist of two tutor-marked
assignments (TMA) for this course.
Instructions for Formatting Your Assignments
Before attempting the assignment please read the following instructions carefully:
1) On top of the first page of your TMA answer sheet, please write the details exactly in the following
format:
ENROLMENT NO.:……………………………………………
NAME :……………………………………………
ADDRESS :……………………………………………
……………………………………………
……………………………………………
COURSE CODE:
…………………….
COURSE TITLE :
…………………….
ASSIGNMENT CODE: ………………….…
STUDY CENTRE: ………………..…..
DATE
:
….………………………………………...
PLEASE FOLLOW THE ABOVE FORMAT STRICTLY TO FACILITATE EVALUATION AND
TO AVOID DELAY.
2) Use only foolscap size writing paper (but not of very thin variety) for writing your answers.
3) Leave 4 cm margin on the left, top and bottom of your answer sheet.
4) Your answers should be precise and in your own words. Do not copy answers from study material.
5) While solving problems, clearly indicate the question number along with the part being solved. Write
units at each step of your calculations as done in the text because marks will be deducted for such
mistakes. Take care of significant digits in your work. Recheck your work before submitting it.
6) This assignment will remain valid until June 30, 2008. However, you are advised to submit TMA-1
within
8 weeks and TMA-2 in 12 weeks of receiving this booklet to accomplish its purpose as a teaching-tool.
We strongly recommend that you should retain a copy of your assignment response to avoid any
unforeseen situation. If possible, please attach a photocopy of this assignment along with your response.
You could obtain response to the difficulties you may face in PHE-10 course via e-mail by writing to
[email protected]. Please note that, we do not provide answers to Assignment questions.
We wish you good luck.
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Tutor Marked Assignment-1
Electrical Circuits and Electronics
Course Code: PHE-10
Assignment Code: PHE-10/TMA-1/2007-08
Max. Marks: 100
Note: This assignment is based on Blocks 1 and 2. Attempt all questions. Marks for each question are
indicated against it.
1. State, with reasons, whether the following statements are True or False:
i)
ii)
Transformer is a passive device hence it cannot boost voltage.
Reciprocal network can be built using diode and transistors.
iii)
A frequency selective circuit (like filter) can be built by using combination of only
resistors.
iv)
Practically it is impossible to have a resonant circuit with infinite Q.
v)
vi)
Silicon can be doped with germanium to obtain p-type semiconductor.
Centre tapped transformer is necessary for functioning of a bridge rectifier.
vii) Amplifier with common collector mode offers maximum voltage gain.
viii) A greater than unity results into sustained oscillations.
2.
ix)
High pass filter is used in voltage regulator circuit after rectifier stage.
x)
If two amplifiers of gain A1, and A2 are cascaded, the resultant gain is A1 + A2.
a)
Calculate the value of resistor R in the circuit shown in Fig. 1. (Three current values
are shown with their directions of flow.)
(210)
(7)
Fig. 1
b)
In the practical current source shown in Fig. 2, Is = 10 A and Rs = 10 Ω. Convert this
into a practical voltage source.
Fig. 2
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(3)
3.
A series LCR circuit with L = 400 mH, C = 20 nF and R = 250 Ω is connected to an ac
source of
65 V. Calculate the resonance frequency and Q of the circuit. What is the current flowing
through the circuit and voltage across the capacitor at resonance frequency?
(10)
4.
a)
b)
5.
Design a band pass filter to pass the frequencies between 100 kHz and 200 kHz.
Design and draw a circuit of a symmetrical lattice type attenuator to give attenuation
of 20 dB and to have characteristic impedance of 200 Ω.
(4)
What are the major causes of charge carrier transport in uniformly doped n-type
semiconductor? Explain in brief.
(5)
Calculate the value of load impedance at 100 Hz to achieve maximum power
transfer from a source with 10 Ω resistance and 100 mH inductance.
(5)
Explain the basic difference between the construction and biasing of enhancementtype and depletion-type MOSFETs.
(6)
Draw the biasing circuit (indicting proper polarities) for a common collector amplifier
using p-n-p transistor.
(4)
What is an operating point, Q of a transistor? How is a Q point for class A amplifier
chosen? Why class C amplifier is not used in audio amplifiers?
(5)
b)
Design and draw a circuit of a Colpitt’s oscillator to provide 100 kHz frequency.
(5)
a)
Refer to the universal bias shown in Fig. 4.11(c), of your study material. If
VCC = 20V, R1 = R2 = 20 kΩ, RC = 3 kΩ, RE = 5 kΩ, VBE = 0.7 V and  = 50, calculate
VB, VE, VC, IE, IB and VCE.
(6)
b)
Explain the working of Wein bridge oscillator.
(4)
a)
Design and draw a circuit of a transformer, rectifier and filter for providing 10V, 1A
unregulated dc voltage from 220V ac supply. Mention the required turns ratio of
the transformer; current ratings of primary and secondary windings; diode ratings
and filter capacitor voltage rating.
(6)
Design a Zener voltage regulator to provide a 8V dc voltage with 1 A load current
using a 10V unregulated dc supply designed in the above question. Specify the
voltage and power ratings of all components used.
(4)
a)
b)
6.
a)
b)
7.
8.
9.
a)
b)
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(6)
Tutor Marked Assignment-2
Electrical Circuits and Electronics
Course Code: PHE-10
Assignment Code: PHE-10/TMA-2/2007-08
Max. Marks: 100
Note: This assignment is based on Blocks 3 and 4. Attempt all questions. Marks for
each question are indicated against it.
1. State with reasons whether the following statements are true or false:
i)
ii)
Op-Amp 741C has only five pins.
An ideal Op-Amp has infinite voltage gain; this means that at the output we should get
infinite voltage.
iii)
If the output voltage of an Op-Amp is not equal to its saturation voltage then the
differential input voltage is zero.
iv)
v)
In non inverting Op-Amp the closed loop gain can not be less than 1.
IC LM380 is a small signal amplifier used to amplify the voltage.
vi)
Conversion of a two digit decimal number into its binary equivalent and BCD
equivalent leads to the same binary digits.
NAND and NOR gates are said to be the universal gates.
vii)
viii) In D-Flip flop, if both preset and clear terminals are zero state, we get “no change”
state at the output.
xi) Synchronous counters are faster than the ripple counters.
x) In cathode ray tube electron beam deflection is caused by magnetic field.
2.
a)
b)
c)
(210)
What is the difference between Input offset voltage and output offset voltage?
Write their significance.
(2+2)
Draw and explain the ideal voltage transfer curve for an op-amp. Why is the
output voltage always less than the supply voltage?
(2+1)
Trace the output waveform of the circuit given in Fig. 1(a) for the input
waveform shown in Fig. 1(b)
(3)
+12 V
vin (V)
vin
+5
vo
0
t (s)
10 kΩ
-5
-12 V
(a)
(b)
Fig.1
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3.
a)
Explain the working of 4input inverting adder. In which condition will it work as
an averaging amplifier?
(2+1)
b)
In the amplifier circuit shown in Fig. 2; find out (i) the gain, (ii) output voltage, V0
and (iii) ouput current I0
(1+1+2)
80 kΩ
+15 V
IF
vI=+1.5V
10 k Ω
IO
II
vo
IL
6 kΩ
-15 V
Fig. 2
c)
4.
a)
Design and draw the basic differentiator circuit with RC time constant 1s. Draw
the output waveform for the input signal of V= 2 sin (10πt) with t expressed in
second.
Draw a circuit of variable gain amplifier using IC LM380 with a variable gain upto
50 for audio frequency.
5.
(3)
(2)
b)
Write down the importance of dropout voltage in a voltage regulator IC. Why the
dropout voltage should not be too large in a voltage regulator IC?
(2+1)
c)
Using IC LM317, design an adjustable voltage regulator for an output voltage of 2
to 10 V. If the dropout voltage and the ripple voltage for this IC is 3 V and 2 V,
respectively, then what the minimum voltage that should be applied at the input to
get 10 V output?
(3+2)
a)
Write the ASCII code for Indian
(2)
b)
What is the hex equivalent of 11001001001110011.11010112
(3)
c)
What is the BCD code of 83710
(2)
d)
Multiply 1110.112 by 11.012
(3)
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6.
a)
Realise three input NOR gate using diodes and transistor.
(3)
b)
Obtain a Boolean expression from the truth table given in Table 1. Simplify it and
find the MSP expression. Realise this MSP expression using only NAND gates (1+3+3)
Table: 1
A
0
0
0
0
1
1
1
1
7. a)
B
0
0
1
1
0
0
1
1
C
0
1
0
1
0
1
0
1
Y
1
0
1
1
0
1
0
1
For the R and S inputs shown in Fig. 3, draw the output Q of an RS flip flop.
(4)
1
S
0
1
R
0
Fig. 3
b)
8. a)
b)
c)
9. a)
b)
c)
What do you mean by edge triggered flip-flop? Give the truth table for a positive edge
triggered R-S flip-flop. What would be the output if the clock is absent?
(6)
Design a mod-6 ripple counter using J-K flop-flop.
(3)
What do you mean by RAM and ROM in semiconductor memories? Which of these
are volatile and why?
(2)
A 4bit DAC produces 21 mV output for a digital input of 1110. What is the
resolution for this DAC? Find out the Vout for 0101.
(3+2)
Show that, in a flux meter, deflection is directly proportional to a change in flux
of the search coil.
(3)
What is meant by deflection sensitivity of a cathode ray tube? Obtain an expression
for it.
(3)
What is meant by duty cycle of a pulse? If ON time of a pulse is 10 s and its time
period is 25 s then find out its duty cycle. Is it a square wave?
(1+2+1)
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FEEDBACK ON “ELECTRICAL CIRCUITS AND ELECTRONICS” (PHE-10)
Dear Student,
We are under process of revising the course material of PHE-10. We hope that you are studying
this material and are completing the assignment responses. We would like to get your feedback
on this course while you are studying it. Since this material is specially developed for you, your
suggestions will be highly appreciated and it will help us in the revision process.
We request you to spend few extra minutes to fill the feedback questionnaire and send it to us.
Please send this feed back questionnaire to:
The Course Coordinator (PHE-10),
School of Sciences, D-Block New Academic Complex,
Indira Gandhi National Open University (IGNOU),
New Delhi 110 068.
HOWEVER, PLEASE SUBMIT YOUR ASSIGNMENT
RESPONSES AT YOUR STUDY CENTRE. DO NOT SEND
THEM WITH THIS QUESTIONNAIRE.
We wish you all the very best.
(Course Coordinator)
PHE-10
1.
Personal information
a. Name : ………………………………………………………
c. Date of Birth: ……………………….
b. Male / Female
d. Enrolment Number : …..………………..
e. Address:……………………………………………………………………………….
…………………………………………………………………………………………
f. E-mail:……………….………………
g. Tel. No:…………………………………
h. Study Centre Code and Name:.…………………………..…………………………...
i. Are you employed?
YES/NO
If yes, please specify the nature of the job…………………………………………..…..
…………………………………………………….……………………………………..
j.
You have access to computer at :- (a) Home- Yes/No (b)Friend’s home -Yes/No
(c) Cyber Café –Yes/No (d)Study center Yes/No.
[Put tick mark () at each Yes/No]
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2.
Delivery Mechanism
a)
Are the counseling sessions for PHE-10 arranged at your study centre?
YES/NO
If Yes, how many?…………………………………………………………………
b)
Do you attend counseling session of PHE-10 held at your study centre?
YES/NO
If Yes, do you find these sessions useful?
YES/NO
If No, state the reasons…….…………………………………………………………
………………………………………………………………………………………
c)
Are the number of sessions adequate?
YES/NO
If No, how many sessions do you expect?...................................................................
3.
Multimedia in Learning
a)
Would you prefer teleconference mode of counseling over face-to-face counseling
at the Study Centers?
YES/NO
Explain why...….…………………………………………………………………
….………….………………………………………………………………………
b)
Will it be possible for you to attend the teleconferencing session on weekdays?
YES/NO
Any preferred timings?……………………………………………………………
c)
Give your suggestions about using multimedia facilities for IGNOU course
delivery. (Use additional pages if you answer is long.)
………………………………………………………………………………………
………………………………………………………………………………………
d)
Do you use computer during your studies?
YES/NO
If yes, specify the purpose.
.....……………………………………………………………………………………
……………………………………………………………………………………
Which software packages do you use?
………………………………………………………………………………………
………………………………………………………………………………………
4.
Please fill in the enclosed Table for unit-wise feedback. You may like to read the
instructions given above the Table before starting to fill up the Table.
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Unit-wise feedback for PHE-10
Note: Please tell us about your difficulties in studying each of the units. To describe your response, you may put an appropriate number from 1 to 8 below in
each cell regarding different aspects of a unit. The name of unit is given in each row. Choose a number closest to your view:
Not clear (1); Not sufficient (2); Difficult (3); Not relevant (4); Not interesting (5); Satisfactory (6); Understandable (7); Excellent (8).
In the last column, you have to mention the approximate time you have taken to study each Unit.
Please make sure that you have filled in all the 104 cells.
Unit
Explanation
of Concepts
Examples
given
Language
used
Mathematics
used
1. Circuit Analysis
2. DC and AC Circuits
3. Electron Devices
4. Amplifiers
5. Oscillators
6. Power Supply
7. Operational Amplifier
8. Application of Operational
Amplifiers
9. Linear ICs-Amplifiers and
Voltage Regulators
10. Number System and Codes
11. Fundamentals of Boolean
Algebra and Flip Flops
12. Registers, Counters, Memory
Circuits and A/D Converters
13. Electronic Instruments
18
Figures
Tables
SAQs and
Terminal
Questions
Time taken to
study the
unit (min./h.)
5.
If you have filled numbers 1 to 5 in any of the cells of the above Table, please write your
suggestions/problems for that specific aspect of the concerned unit. (Use additional pages if need
be).
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6.
What (e.g., explanations, diagrams, examples, definitions, etc.) would you like to be added or
deleted in the units to make it easier to study? (Use additional pages if your answer is long).
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7.
Give your suggestions about any new concepts/topics to be introduced in this course. Also
mention if you would like to delete any topic with reason. (Use additional pages if your answer is
long).
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