It´s applied an unit step of 10V on the input of a RC Series Circuit, it is known that resistor value is 1 Kohms, determine the value of the capacitor knowing that took it 10 seconds to charge it.

THESE ARE THE QUESTIONS FROM THE SUBJECT POWER SYSTEM FUNDAMENTALS AND THE TOPIC IS MECHANICAL DESIGN OF OVER HEAD LINES AND THE ANSWERS ARE IN BRCKETS

1) Estimate the corona loss for a three-phase, 110 kV, 50 Hz, 150 km long transmission line consisting of three conductors each of 10 mm diameter and spaced 2·5 m apart in an equilateral triangle formation. The temperature of air is 30ºC and the atmospheric pressure is 750 mm of mercury. Take irregularity factor as 0·85. Ionisation of air may be assumed to take place at a maximum voltage gradient of 30 kV/ cm. [316·8 kW]

2). Taking the dielectric strength of air to be 30 kV/cm, calculate the disruptive critical voltage for a 3-phase line with conductors of 1 cm radius and spaced symmetrically 4 m apart. [220 kV line voltage]

3). A 3-phase, 220 kV, 50 Hz transmission line consists of 1·2 cm radius conductors spaced 2 m at the corners of an equilateral triangle. Calculate the corona loss per km of the line. The condition of the wire is smoothly weathered and the weather is fair with temperature of 20ºC and barometric pressure of 72·2 cm of Hg. [2·148 kW]

1. How does Wireless Ethernet architecture, prevents the hidden node problem?
   1. Ding real time transmission
   2. Handshaking after transmission of data
   3. Handshaking before transmission of data
   4. Acknowledgement of every packet transmitted

2. What is the purpose of the Network Address Translation (NAT)?

1. To divide the network into subnet works
2. To receive all data sent to private networks
3. Allow private IP addresses to work
4. Convert private IP addresses to public IP addresses

3. The binary number 1011111 is equivalent to which decimal number below

1. 125
2. 65
3. 128
4. 95

4. Which word or phrase below best describes a subnet mask

1. A thing you put on your face
2. A filter
3. Creates the IP address for the network
4. Determines the path of data to the sub-network

5. The packet by which data is transmitted on ethernet architecture is called a frame. How many bytes is the length of that frame?
   1. 47 – 1500 bytes
   2. 46 – 1500 bits
   3. 46 – 1500 bytes
   4. Too many bytes to count

6. In ethernet architecture the most common topology used is
   1. Bus
   2. Extended star
   3. Wireless
   4. star

One transistor amplifier BJT 1.Design a single transistor amplifier BJT with appropriate coupling and bypassing capacitors. 2.Draw the DC equivalent circuit and find the Q point. Draw the AC equivalent circuit and find parameters of your full amplifier circuit (gain and input resistance) . 3.Simulate the FULL amplifier circuit in DC state, indicate the Q point on the diagram and compare with theoretical results. 4.Simulate the FULL amplifier circuit using appropriate sin input signal(s). Using the simulation results from the graph, find the same amplifier circuit parameters, and compare with theoretical result. Draw your conclusions.

PWrite a VHDL function that accepts a vector of arbitrary length and integer that specifies the number of bits the input vector to be rotated to the left and returns another vector. For instance functions accepts two inputs: 0101011 and 3 and it returns 1011010.

Why do you think it is important for an electrical engineer to measure variability?

Write a program that asks the user to enter an array of 8 characters then you have to check if characters ‘b’ or ‘a’ appears within the characters and replace them with ‘B’ or ‘A’. For example you enter “a m a l a a b d” The output should be “A m A l A A B d”

During lab 4, we have seen numerical implementation of Fourier Series for periodic signals. As first part of this assignment, you need to write a Matlab function that would take an array representing a single period of a signal (x), corresponding time array (t), and return the Fourier Series coefficients (Ck) in exponential form. The function should also be able to take two (2) optional input arguments: number of Fourier coefficients (Nk) and plot option (p). Use the template ‘fourier_series_exp.m’ for this problem.

(Template "fourier_series_exp.m")

function [Ck]=fourier_series_exp(x,t,Nk,p)

% Ck = exponential fourier series cofficient
% x = single period of a signal
% t = time corrosponding to 'x'
% Nk = (optional input) number of exponential terms
% p = plotting option ; p=0, no plots, p = 1 plot Ck vs k and reconstructed signal
% dT = t(2)-t(1) = temporal resolution of signal (x)
% T = peiod of signal 'x'
% w0= angular frequency of signal 'x'

dT=t(2)-t(1);
T= dT*length(t);
w0=2*pi/T;   

% Check the number of inputs, 'nargin' returns number of input arguments
if nargin <2
error('Not enough input argument!')
elseif nargin == 2
Nk=101; % you can set any default value you like
p=0; % not plots
elseif nargin ==3
p=0; % not plots
end
k=-floor(Nk/2):floor(Nk/2); % if Nk=11, k=-5:5; if Nk=12, k=-6:6

%% evaluate Ck
%
% % % write this code segment
%
%% plot spectrum and reconstructed signal   
if p==1
% plot abs(Ck) vs k and angle(Ck) vs k
%
% % % write this code segment
%
  
% plot 3 cycles of the signal 'x' and the reconstructed signal
%
% % % write this code segment
%
end

end

For a parallel RLC circuit operating under initial conditions only:

a) Give detailed discussion of different types of response.

b) Show how to determine solution constants from initial conditions.

c) Support your analysis with terminal voltage plot using numerical quantities on your choice.

Hint: Use different values of R to clarify each response type for the same values of L and C for all cases.

Consider the classical power system where one generator is connected to the infinite bus through two transmission lines. We want to study the transient stability for a fault on one of the two lines. The generator parameters are as follows: Pm = 1, H = 4, KD = 5, x'd = 0.25, E' =1.4. The transmission line where the fault occurs has a line reactance of 0.6 pu. The other transmission line that remains in service has a line reactance of 0.75 pu.a) Suppose the fault occurs at the middle of the line. Write out the swing equations for the pre-fault,fault-on and post-fault systems.

MATLAB ONLY:

Write a user defined method MaxPath()

Find the maximum path sum in matrix. The maximum path is sum of all section from first to last
row where you can move only down or at a angle to left or right. You can start from any section
in first row of given matrix of P*Q.
Input: mat [] [] = 10 10 2 0 20 4
1 0 0 30 2 5
0 10 4 0 2 0
1 0 2 20 0 4
Output: 74
The maximum sum path is 20-30-4-20.
Input: mat [] [] = 1

Design a second-order band-pass filter using resistors and capacitors for a microphone for a hearing aid, which allows signals in the range of 1 to 16 kHz to pass through. For the component values that you chose, at what frequency is the transfer function at a maximum?

Briefly explain the difference between input bias current and input offset current and the ideal, practical values for both currents.

A semiconductor diode, the forward and reverse characteristics of which can be considered ideal, is used in a half-wave rectifier circuit supplying a resistive load of 1000Ω. If the r.m.s. value of the sinusoidal supply voltage is 230 V determine: (a) the peak diode current; (b) the mean diode current; (c) the r.m.s. diode current; (d) the power dissipated in the load