Q3)
A three-phase, Y-connected, 220 V, 13 kW, 60 Hz, six-pole induction motor has the following
parameter values in Ω/phase referred to the stator:
R1 = 0.3 Ω. R2' = 0.15 Ω
X1 = 0.5 Ω. X2'= 0.21 Ω Xm = 13.25 Ω
The total rotational losses are 450 W. The core loss is lumped in with the rotational losses. For a slip of 0.02,
and based on approximate equivalent circuit, determine:
(i) The rotor speed.
(ii) The stator current.
(iii) The power factor of the motor.
(iv) The input power of the motor.
(v) The developed mechanical power.
(vi) The efficiency of the motor.

please say why you have chosen this answer in details also please clear hand writing thanks in advance

(v) When doping a semiconductor p type, the bulk of the material has:

      A positive charge

       A negative charge

       Is neutral

        Will only get a positive charge when we apply a voltage

Explain why you chose this answer:      

(vi) In order to generate free charge carriers by optical excitation, the wavelength of the incident light needs to be:   

      Monochromatic (single wavelength)

       Longer than the cut-off wavelength of the material

       Shorter than the cut-off wavelength of the material

        Of a very high intensity to penetrate the material

Explain why you chose this answer:

(vii) Light of the correct wavelength to produce optical excitation is incident on a piece a p-type Si. This will produce:

      A greater number of holes than electrons

       A greater number of electrons than holes

       A greater change in the number of holes relative to the number before illumination

        A greater change in the number of electrons relative to the number before illumination.  

Explain why you chose this answer:

(viii) Compared to silicon, compound semiconductors such as GaAs will always:

      Have a direct bandgap

       Be more expensive to produce

       Be easier to dope  

       Allow us to easily vary the bandgap.   

Explain why you chose this answer:

Please write and solve one question about identical transformer (parametric). Also, please write and solve one more question about real transformer (numerical). You can get help from the Electric Machinery. A.E. Fitzgerald book. (Add approximations if any) I'm waiting for two questions with answers to learn transformers in detail.

Consider an ideal down converter supplying load resistance of 80 ohms from a voltage source rated 9V and 250mA. The converter operates at 70-kHz and is designed for 5% voltage ripple and 10% current ripple with a duty time of 60%.

a) Calculate the output voltage, output voltage ripple, output current and output current ripple.

b) Calculate the cycle period, T on and T off.

c) Calculate the required inductance and capacitance values

d) Calculate the output voltage as functions of time

e) Graph the ideal output voltage and inductor current waveforms.

Create a comparative table of advantages and disadvantages of active, passive and digital filters.

THESE QUESTONS ARE FROM THE SUBJECT POWER SYSTEM FUNDAMENTALS AND FROM THE TOPIC ELECTRICAL DESIGN OF OVER HEAD TRANSMISSION LINES AND MAKE SURE THAT YOUR ANSWER IS CORRECT

Problem-1

A single phase transmission line has two parallel conductors 1·5 meters apart, the diameter of each conductor being 0·5 cm. Calculate line to neutral capacitance for a line 80 km long.

Problem-2

A 200 km, 3-phase transmission line has its conductors placed at the corners of an equilateral triangle of 2·5 m side. The radius of each conductor is 1 cm. Calculate : (i) line to neutral capacitance of the line, (ii) charging current per phase if the line is maintained at 66 kV, 50 Hz.

Problem-3

A single-phase line has two parallel conductors 1 meter apart. The radius of each conductor is 0·5 cm. Calculate the loop inductance per km of the line

Q2) Having the text (A AA BACBCCBBAAADBBBC D), answer the following: 1. The probability of character A( P(A)) equals------- a) 1 b)0.1 c) 0.7 d) 0.35 The self-information of character C( I(C) Jequals------ 2. a) 2.321 bit b) 4.256 bit c) 1.336 bit d) 6.874 bit 3. If the average time t is 5 usec, then the information rate R(x) is-- a) 10.856 Mbps b) 9.486 Mbps c) 7561 kbps d) non of the mentioned

Design and simulate a triangle wave generator with f_o=1.5 kHz and V_o(pp) = 5V

please use online multisim

Question :01 Part A

The initial conditions of a d.c. motor are:
K’ = 3:0Vs
V1 = 24:0V
Td = 18Nm
Ra = 2 ohm
For a 50 percent increase in the armature voltage, calculate the percentage Change in the no-load speed. Assume that the load torque is unchanged.

Is the increase in speed proportional to increase in armature voltage give reson for your answer.
speed.

Part B:

A 50 V, d.c. shunt motor drives a constant-torque load at a speed of 1200 rpm. The armature and field
resistances are 2 ohm and 100 ohm, respectively. The motor draws a line current of 15 A at the given
load.
(a) Calculate the change in voltage to open the motor to holding position(holding position mean "Yes stopping motor electrically"). And plot the change in
speed with bith the voltages.
(b) Calculate the resistance that should be added to the armature circuit to reduce the speed by 50
percent.
(c) Calculate the resistance that must be added to the armature circuit to open the motor at the
holding condition.
(d) Plot all the resistance for change in speed.

use matlab

y(t)=10*(cos(2*pi*500*t)+cos(2*pi*1000*t)+ cos(2*pi*1500*t)).

e) Down sample y(t) by a factor of 6. Sketch the Fourier transform with appropriate frequency axis. Check if all frequency components are correct?

Up-sample the time-domain signal obtained in e) by a factor of 6. Use appropriate filter for interpolation. Sketch the Fourier transform of the up-sampled and filtered signal. Does the resulting signal show all frequency components of the original signal y(t)?

The signal output from a certain process in an industry is described by the following equation

h (t) = 5 cos 2π1000 t + 7 cos 2π 2000 t + 2 cos 2π 3000 t.

Suggest any two remedial measures to avoid any problems that occurred during the

reconstruction process.

THESE QUESTONS ARE FROM THE SUBJECT POWER SYSTEM FUNDAMENTALS AND FROM THE TOPIC ELECTRICAL DESIGN OF OVER HEAD TRANSMISSION LINES AND MAKE SURE THAT YOUR ANSWER IS CORRECT

Problem-4

Find the inductance per km per phase of a 3-phase overhead transmission line using 2 cm diameter conductor when these are placed at the corners of an equilateral triangle of side 4 meters.

Problem-5

The three conductors of 3-phase overhead line are arranged in a horizontal plane with a spacing of 4 m between adjacent conductors. The diameter of each conductor is 2 cm. Determine the inductance per km per phase of the line assuming that the lines are transposed.

In a localized capacitance method for a Long transmission line what could be consider a drawback from it? Also when a long transmission line is open circuited on its receiving end, would there be any current at the sending end?