ECE 4th SEM IMP QUESTIONS
IMP QUESTIONSElectronic Instrumentation and Measurements
Q.1. Calculate the maximum percentage error in
the difference of two measured voltages when V1 = 200 V ± 2 % and V2 = 50
V ±6 %.
Q.2 Derive the equation for percentage error
for product of quantities of two or more
quantities.
Q.3. Define accuracy, precision and resolution.
How they are different from each other.
Q.4. Give applications of CRO. Why trigger
circuit is used in CRO.
Q.5. A 0-300 V voltmeter has 600 scale
divisions which can read to 1/2 division. Determine the resolution of the meter in
volt.
Q.6. Explain the function of horizontal and
vertical amplifier in CRO.
Q.7. Describe the construction of PMMC
instrument.
Q.8.The voltages at opposite ends
of a 470 ohms, ±5% resistor are measured as V1=12 V and V2 = 5
V. The measuring accuracies are ±0.5 V
for V1
and ±2% for V2.Calculate the level of current
in the resistor and specify its accuracy.
Q.9. Discuss in detail cathode ray
oscilloscope?
Q.10. Sketch the circuit diagram to show how a
PMMC instrument can be used as
DC ammeter. Also explain their circuit
operation.
Q.11. Derive the expression for the
electrostatic deflection in the CRT?
Q.12. Explain how electrostatic focusing helps
to focus the electron beam on the CRT screen.
Q.13. Explain different types of forces
operating inside the PMMC instrument.
Q.14. An 820 ohm resistance with an accuracy of
±10% carries a current of 10 mA. The current was measured by an analog ammeter on a
25 mA range with an accuracy of ±2% of full scale. Calculate the power
dissipated in the resistor and determine the accuracy of the result.
Q.15.
Explain the operation of delay time base system.
Q.16. It
is desired to measure the value of current in the 200 ohm resistor by
connecting a 100 ohm ammeter. Find the actual and measured value of current.
Also find the percentage error and the accuracy.
Q.17. Derive the torque equation for a PMMC
instrument and show its scale is linear.
Q.18. Explain the working of Cathode Ray Tube
with neat diagram.
Q.19. What are different types of errors occur
in measurement of any quantity. Explain each
error with examples.
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Signals and Systems
Jan 01, 2013Posted by Abhi Raj
e-t;
t ≥ 0
(i)
What
is time varying and time invariant system?
(ii)
What
is superposition condition or theorem for systems?
(iii)
Find
total energy contained in the Impulse function.
(iv)
Differentiate
in brief
(a) Energy and Power signals (b)
Even and Odd signals
(v)
Find
the fundamental period of the discrete time sinusoidal signal x[n] = 5cos[0.2Πn]
(vi)
9Find
the fundamental period of each discrete time sinusoidal signal
x[n] = 2sin [6Πn/35]
(vii)
A
pair of sinusoidal signal with a common angular frequency is defined by
x1[n] = sin[5∏n] and x2[n] = 4 cos[5∏n] . Both signals are periodic. Find their
fundamental periods and the fundamental period
of x[n]= x1[n] + x2[n]
(viii)
Find the Laplace Transform and ROC of unit
step function.
(ix)
Find
the ROC of LT of unit ramp function.
(x)
Derive the relationship between Continuous
Time Fourier Transform (CTFT) and Laplace Transform.
(xi)
Explain
Dirichlet’s conditions for the convergence of DTFT.
(xii)
Explain
Dirichlet’s conditions for the convergence of CTFT.
(xiii)
State
and prove time shifting property of z- transform.
(xiv)
State
the condition for stability and causality of Discrete Time LTI system in terms
of ROC of its system function.
(xv)
A
discrete time signal x[n]={ 0, 2 ,3 ,4,5,6,7,8,1,2}
Draw i) x[2n]
ii) x[n-4] iii) x[2-n]
(xvi)
Establish
the relationship between convolution and correlation function for CT system.
(xvii)
Show
that the system y[n] = 7x[n] + 5 is nonlinear system.
(xviii) Show that the given system is
nonlinear system.
(xix)
(a) y(t) = x2(t)
(xx)
What
do you mean by Group Delay?
(xxi)
Write the mathematical expression for the sinc
function.
(xxii)
Write
the condition for the convergence of DTFT.
(xxiii) Find Laplace Transform of unit step
function.
Define
the stability of the system.
(i)
Check the linearity for the system equation
y(t) = t x(t)
(ii)
Find the impulse response of the system having
gain A.
(iii)
Check the causality of the system having
input-output relation y(n) = x(n-1) + x(n-2).
(iv)
Find
the total energy and total power contained in the unit step signal u(t).
(v)
Find the fundamental period of the signal
cos10πt.
(vi)
What will be the odd part of the signal
cos2ωt.
(vii)
Find
the output of an LTI discrete time system for x(n)= (1/2)n u(n-2) whose impulse
response is unit step sequence.
(viii)
Signal
x(t) is shown in the Figure 1.
(i)
Find
x(-4t+5) + 2x(t) for the signal given in figure 1.
Find the
even and odd part of the signal given in figure 1.
(XXII) State and prove Parseval’s theorem
for CTFT.
A triangular pulse signal is shown in above
figure 2. Sketch each of the following derived from x(t)
i)
x(3t) (ii)
x(2(t+2))
(iii) x(3t+2) (iv) x(3t)+x(3t+2)
(XXII) Find the DTFT of the sequence x (n) =
n an u(n).
(XXIII) For the system specification y (t) =
t x (2t) find whether the system is Linear or Nonlinear, static or dynamic, fixed or time varying,
causal or non-causal.
(XXII) For the system specification y (t) =
x (3t+2) find whether the system is Linear or Nonlinear, static or dynamic, fixed or time varying.
xxiv)
Find
the Laplace Transform of e-7t Sin ωt u(t).
xxv)
Find
the Fourier Transform of Signum function.
xxvi)
Find
the Laplace Transform of the signal t sin ωt u(t).
xxvii) Derive any Four properties of DTFT.
xxiv)
Determine the frequency response and impulse
response of a causal Discrete time LTI
system that is characterized by the difference
equation given as
Y[n] - Ay [n-1] = x[n ] with |A| < 1
xxv)
Determine the DTFT of the discrete time
periodic signal X[n] = cos w0
with
fundamental frequency w0 = 2П
/ 5.
xxvi)
State
and prove Differentiation property in frequency domain for z-transform.
xxvii) Determine the impulse response of a
continuous-time LTI system described by first order differential equation
a dy(t)/dt + y(t)
= x(t)
xxviii) Two systems are described by the
following input-output relations:
y(t) = {Cos(3t)} x(t) and
y[n]=x[n-2] +x[8-n]
Check the properties of
linearity, time-invariance, Causality and
Stability for these systems and give
explanation for your answers.
xxix)
Find the output of an LTI system having input
x(t)=1 for 0 < t < 2 and impulse response h(t)= 2
for 0 < t < 5 .
xxx)
Find
the impulse response of the system whose input-output relation is given as y (n)-y (n-1) +3/16
y(n-2)= x(n)- ½ x(n-1).
xxxi)
Find the DTFT of the sequence x (n) = n an
u(n).
xxxii) State and prove time shifting property of
CTFT.
xxxiii) Derive the Differentiation in
frequency domain and convolution properties for z- transform.
Prove that for an energy signal, its
auto-correlation function and its energy spectral density (ESD) are Fourier
transform pairs.
xxiv)
For
following second order differential equations for causal and stable LTI system,
describe whether the corresponding impulse response is under damped, critically
damped or over damped?
xxv)
d
2 y (t)/dt2 + 4dy (t)/dt + 4y (t) = x (t).
xxvi)
What are the ideal frequency selective
filters? Explain
xxvii) The discrete-time signal x[n] is defined as
below
x[n] = 1, when n = 1, 2
-1, when, n = -1, -2
0, when n=0,
│n│>2
Sketch the x[n] and the time shifted
y[n] =x [n+3]
xxviii) Show graphically that δ[n]= u[n] – u[n-1]
xxix)
Sketch signal x(t) = A[u(t+ a) – u(t – a)].
Identify whether it is power or energy signal and accordingly calculate suitable
quantity.
xxx)
Find the Laplace Transform of t x(t), if x(t) is having Laplace Transform X(s).
xxxi)
Find inverse Laplace transform of the
following
xxxii) X(S) = 10/ (S+1) (S+5), ROC : Re{S} < -5
xxxiii) Consider the rectangular pulse (gate pulse)
signal defined as
x(t) = A rect (t/2T) = A;
│t│< T
0; │t│> T
xxxiv) Find the Fourier transform of x(t).
xxxv)
For
a DT system, H(z) is given below ,
H(z) = 3 - 4Z-1/ 1 - 3.5Z-1 +
1.5Z-2
Specify the ROC and determine h[n], when (i)
System is stable (ii) System is causal.
xxxvi) Find out Z- transform of signal x[n] = an u[n]
and its ROC.
xxxvii) Find the impulse response of the system
whose input-output relation is given as
y (n) - y (n-1) + 3/16 y(n-2)= x(n) – ½ x(n-1).
xxxviii) Find the convolution of following two
sequences:
x[n]=
u[n], h[n]= 2n u[n].
xxxix) Explain Invertibility and causality properties
of any system.
xl)
Derive the condition of mapping from s-plane
to z plane and also correlate the ROCs of LT and ZT.
xli)
For
following second order differential equations for causal and stable LTI system,
describe whether the corresponding impulse response is under damped, critically
damped or over damped?
4d2 y (t)/dt2
+ 5dy (t)/dt + 4y (t) = 7 x (t)
xlii)
Define distortion less transmission through a
filter. Derive the frequency response of a filter that will not distort any
signal.
xliii)
Write
the expression for Rxy(τ) and Ryx(τ) and give all the relationship for real
valued and complex valued signals.
xliv)
Find
the step response of the RC high pass filter.
xlv)
Identify whether signal x(t)= e-5t
u(t) is energy signal or power signal? Also calculate energy and power of
signal.
xlvi)
The discrete-time signal x[n] is defined as
below
x[n] = 1, when n = -1,1
0, when n=0, │n│>1
Sketch x[n] and find y[n]= x[n] + x[-n] with
suitable sketch.
liv)
Explain causal and
anti-causal signals with suitable examples.
xlvii)
Find
the DTFT of the sequence x(n)= a|n| and also draw the magnitude spectrum.
xlviii)
Find
the output of an LTI discrete time system for x(n)= (1/2)n u(n-2)
whose impulse response is unit step
sequence.
xlix)
Find
Z-transform and ROC of Ramp function.
l)
Find
the Energy Spectral Density of the function x(t)= e-│t│
li)
Find
the auto correlation of the sequence x(n)= an u(n) for 0<a<1.
lii)
Explain
Invertibility and stability properties of any system with the help of examples.
liii)
Find
the Laplace Transform of the function x(t) = t2 e-2t cos
ωt u(t).
liv)
Find
inverse Fourier Transform of
δ(ω).
δ(ω).
lv)
Find the Fourier
Transform of the constant signal ‘1’ which extends over entire time interval.
lvi)
Find
inverse Laplace transform of following
X(S) = 10/ (S+1) (S+5), ROC : Re{S} > -1
lvii)
Find
the step and impulse response of the RC low pass filter.
lviii)
Define
distortion less transmission through a filter. Derive the frequency response of
a filter that will not distort any signal.
lix)
Determine
the impulse response and step response of a continuous-time LTI system
described by first order differential equation
a dy(t)/dt + y(t) = x(t)
(lxxv)
Find
the Laplace Transform of the function x(t) = t2cos ωt u(t).
(lxxvi) Find the Fourier Transform of u(t) using
Signum function.
(lxxvii) Find the convolution of two
continuous time signals:
x(t)= 3 cos2t, for all t and y(t)=
et; t < 0
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Electronic Circuit
Jan 01, 2013Posted by Abhi Raj
Q.1 WHAT IS
EARLY EFFECT ? HOW D0ES IT MODIFY THE V-I CHARACTERISTICS OF A BJT?
Q.2
DISTINGUISH BETWEEN THE DIFFERENT TYPES OF TRANSISTOR CONFIGURATIONS WITH
NECESSARY CIRCUIT DIAGRAMS,USING TRANSISTOR.
Q.3 WHAT ARE
THE FACTORS AGAINST WHICH AN AMPLIFIER NEEDS TO BESTABLIZED?EXPLAIN DIFFERENT
TECHNIQES USED FOR BIASING TRANSISTOR AMPLIFIERS.
Q4.EXPLAIN
EFFECT OF BJT INTERNAL AND EXTERNAL CAPACITANCES ON FREQUENCY RESPONSE.
Q.5 WHAT ARE ADVANTAGE OF FEEDBACK IN AMPLIFIER
EXPLAIN NEGATIVE FEEDBACK IN DETAILS
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Laser Systems and Applications
Jan 01, 2013Posted by Abhi Raj
1) Explain
the types of coherence
2) Explain
the types of emission
3)
Explain Gain, Gain clamping, Gain efficiency, Absorption.
4)
Explain population inversion.
5)
The coherence length of sodium light is 2.545x10-2m and its
wavelength is 5890A0. Calculate
frequency and coherence time.
6) Discuss
the spatial coherence as related to the size of the source. Obtain expression
for lateral
width and give its
significance.
7)
Deduce the time -independent Schrodinger’s wave equation.
8) Explain
the different types of pumping techniques.
9)
Derive the relation between Einstein’s coefficient.
10) Explain the characteristics of laser?
11) What
is an optical resonant cavity? What role does it play in a laser?
12)
Discuss de-Broglie theory of matter waves.
13)
Derive an expression for de-Broglie wavelength.
14)
Explain principle, construction and working of Fabry –Parrot resonator.
15) Discuss
on the quantum physics briefly.
16) Deduce the time -dependent Schrodinger’s wave
equation.
17) What is uncertainty principle? Apply it to
prove the non existence of electron in the nucleus.
18) What is Compton effect? Derive an equation for Compton shift.
18) What is Compton effect? Derive an equation for Compton shift.
19) Discuss the dual nature of matter and waves.
20) Calculate the population ratio of two states
in laser that produces light of wavelength 6000A0 at3000 K.
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Computer Architecture & Organization
1(i)Write
down the structural and behavioral aspects of half adder and full adder.
(ii)
Realize half adder and full adder using logic gates.
2.List
various register level component.
3.What
do you understand by design levels in the design of computer systems.
4.Write down the HDL and VHDL of half adder
and full adder.
5.llustrate
the use of state table for a sequential circuit considering one input variable
x, one output variable y and two clocked D Flip flop also use, AND gate, OR
gate, and Inverter.
6.Write
down the component of Processor level.
7.Diagramatically
state the Queuing Model. Write all its derivation/ formulas. Illustrate this model with a
suitable examples.
8.Define
performance measurement along with it
formulas. Design a computer with multiple CPU and Main memory banks.
9.Represent
Diagrammatically the internal organization of CPU and Cache memory.
10. What
do you mean by programmable logic devices? Represent with diagram .
11.Consider
a 5X32 decoder with four 3X8 decoder and a 2X4 decoder.Use a block diagram
representation.
12.Represent
the iterative flow method used by a CAD with a flowchart representation and
discuss the usage of CAD tools.
13.
Design RS Flip Flop using NOR and NAND Gate and analyze its various cases.
14.With the help of logic circuit and logic
diagram classify the shift registers based on the direction of data movement
and mode of input and output.
15. Design
and explain about word gates with the help of NAND and NOR gate
16.
Write down the basic arthematic operations of ALU along with their
different implementations. Design the
logic diagram of arthematic circuit.
17. What
is the basic structure of floating point numbers? Consider
an example to represent it
.
.
18.Write
short notes on
(i)
Multiplexers
(ii)
Word Gates
(iii)
Encoders and decoders
19.Design the followings:
(i)
a 4-bit D register with parallel loads.
(ii) a
register-level design of 4-bit magnitude
comparator
(iii) a
4-bit parallel adder.
20. Design
an eight-input multiplexer constructed
from two-input multiplexers.
.
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