Electrical Circuits

Unit-1

1. Explain how source transformation is achieved. 2. a) Derive the expression for energy stored in an inductor? b) Derive the expression for

energy stored in a capacitor? Derive the expression for energy stored in a resistor? 3. A 25 Ω resistor is connected across a voltage source i) V (t) = 150 sinωt. ii) V (t) =200 sinωt. Find

the current I(t) and the instantaneous power P (t) and also draw the relevant waveforms 4. State and explain KCL and KVL [7] Nov-2010 set-1, 2,4Apr/May 2007 5. A) Write short notes on Star-Delta transformation. b) By taking any one example write down

the procedure to obtain node voltages by using nodal analysis.

Unit-2 1. Derive the expression for R.M.S. and average value of a sinusoidal alternating quantity. 2. a) define the following: i) Frequency ii) Phase iii) Form factor and iv) Peak factor. 3. Single phase circuit consists of three parallel branches the admittances of the branches are

Y1=0.4+j 0.6, Y2= 0.1+j 0.42, Y3 = 0.06+j0.23.Determine the total admittance and impedance of the circuit? Determine (i) currents I1, I2, I3 and I

4. The voltage across and current through a circuit are given by υ =250 sin(314t10o)V I=10sin (314t+50o)A calculate impedance, resistance, reactance of circuit.

5. A resistance of 30 Ω is connected in series with a 120 μ F capacitor across a 230V, 50Hz supply. Determine current through the circuit, phase difference between voltage and current.

Signals & Systems Unit-1

1. Explain the analogy between vectors and signals in terms of orthogonality and evaluation of constant 2. A rectangular function defined as f(t)= A; 0<t<л/2

-A; л/2<t<3 л/2 A; 3 л/2<t<2 л

Approximate the above function by Acost between the intervals (0, 2 л) such that the mean Square error is minimum.

3. Define and sketch the unit impulse function, unit step function and signum function bring out the relation between these two functions

4. State the properties of even and odd functions 5. Find the exponential Fourier series and plot the magnitude and phase spectrum for the triangular waveform

shown in figure

Unit-2

1. Find the Fourier transform of the signal x(t)=2/(1+t2). 2. Find the Fourier transform of the signal shown below: y(t) = cos 10t; −2≤t ≤ 2

0; therwise 3. Obtain the Fourier transform of the following functions: i). Impulse function δ(t) ;ii). DC Signal ;iii). Unit

step function 4. State and prove convolution in time domain, Multiplication in time domain property of Fourier transform. 5. Define sampling theorem for time limited signal and find the nyquist rate for the following signals.

a) sinc20t b) 4 sinc2100t.

Electronic Devices and Circuits

Unit-1

1. Explain the operation of silicon p – n junction diode and obtain the forward bias and reverse bias Volt – Ampere characteristics.

2. Explain the V-I characteristics of Zener diode and distinguish between Avalanche and Zener Break downs

3. In a Zener diode regulator, the supply voltage = 300V, Vz = 220V, Iz = 15mA and load current = 25mA. Calculate the value of resistor required to be connected in series with the Zener diode.

4. Obtain the transition capacitance CT of a junction diode at a reverse bias voltage of 12V if CT of the diode is given as 15 PF at a reverse bias of 8 V. Differentiate between transition and diffusion capacitances

Unit-2

1. Define the following terms of a rectifier and filter: i)Ripple Factor ii)Regulation iii)Rectification

Efficiency iv)FormFactor 2. List out the merits and demerits of Bridge type Full Wave rectifiers over centre tapped

type Full Wave rectifiers 3. Compare the performance of Inductor filter and capacitor filter. 4. Derive all the necessary parameters of centre tapped FWR

Switching Theory & Logic Design

Unit-1

1. Convert the following to Decimal and then to Binary.

(a) 101116 (b) ABCD16 (c) 72348 (d) 77668 (e) 12810 (f) 72010

2. find the 2’s complement of the numbers: (i) 01001110 (ii) 000110101 3. Simplify the following Boolean expressions: a) A’C’ + ABC + AC’ to three literals

b) (x’y’ + z)’ + z + xy + wz to three literals c) A’B(D’ + C’D) + B(A +A’CD) to one literal d) (A’ + C)(A’ + C’)(A + B + C’D) to four literals

4. State duality theorem. List Boolean laws and their duals

Unit-2

1. (i)Simplify the logic function f = AB + A C + C + AD + A B C + ABC ii)Simplify Boolean function F = A’C + A’B + AB’C + BC

2. (i)Find the Complement of the function Y=(A+BC) (B+CA) in its POS form ii)Minimise the function using Karnaugh’s map method F (A,B,C,D) =∑m (1,2,3,8,9,10,11,14) +∑ d(7,15)

3. Draw a logic diagram using only two-input NAND gates to implement the following expression: (AB + A'B') (CD' + C'D)

4. Write the Min terms and Max terms for the following functions F1= Σ(1,4,6,7,9) F2 = Π(3,5,7,11,14)

PTSP IMPORTANT QUESTIONS

UNIT-I

(1). Define probability based on set theory and fundamental axioms?

(2). State and prove Baye’s theorem.

(3). State and prove multiplication theorem of probability.

(4).Explain(i) Joint and conditional probabilities

(ii)Relative frequency definition of probability

(5). Two manufacturing plants produce similar parts .Plant A produce s 4,000 parts, 200 of which

Are defective . Plant B produces 8,000 parts , 300 of which are defective.One part is

selected at random and found to be defective .What is the probability that the part came

from plant B.

UNIT-II

(1). Define Random variable and give the concept of random variable.

(2). What are the conditions for a function to be a random variable.

(3). What do you mean by continuous and discrete random variable.

(4). Define cumulative probability distribution function . And discuss distribution function specific

properties .

(5). A fair coin is tossed three times and the faces showing up are observed .

i)Write the sample description space

ii)If X is the number of heads in each of the outcomes of this experiment,find the probability

function.

iii)Sketch the CDF and pdf.