A2)

i) What is the cause of the junction capacitance and diffusion capacitance of a pn junction? Under what condition the junction and diffusion capacitance of the pn junction will exist?

ii) Is the junction capacitance of a pn junction linear? How about the diffusion capacitance?

a)Differences between asynchronous and synchronous generators? Which one applies in the plants and why?
b)Where do gas and steam turbines apply, not to mention in power plants?
c) What are the main components of the wind generator system or solar-batteries-substation?
d) What is the difference between using the star or triangle connection at the start of an engine?
e) In equipment tests, what is the difference between type, routine and special tests?
f) Why are insulated cables not used in high voltage towers?
g) What are the components of the 220 kV and 500 kV high voltage cables?
h) What are the differences between primary and secondary medium voltage cells?
i) What are the differences between medium voltage cells and GIS cells?

why reactive power limits (Qmin, Qmax) of PV buses should be available as input data

This question is being asked from chapter 5 of the book electric motors and control systems 2nd version and the files attached.

file:///C:/Users/prime/Downloads/ET55a%20Single%20Phase%20AC%20Motors%20%236B.pdf

file:///C:/Users/prime/Downloads/ET55a%20Three%20Phase%20AC%20Motors%20%236A.pdf

1. Why does an induction motor (with a squirrel cage rotor) need “slip” - operating at less than the synchronous speed (the speed in which the magnetic field rotates in the stator)?

Explain, in your own words and without any detailed circuit analysis, why the CE-CB cascode amplifier extends the upper frequency range of the corresponding CE amplifier.   Your explanation should take no longer than half a page and should cover the following points:

1-

• Why CE amplifiers tend to have lower 3 dB upper cut-off frequencies compared to CC and CB amplifiers
• Why the CB amplifier has a higher 3 dB cut-off than the CE

Assume we have a parallel-plate capacitor.

(1) If we increase the distance between the plates, what will happen to its capacity?

(2) If we increase the surface area of the plates, what will happen to its capacity?

(Hint: How do you calculate the capacity of a capacitor?)

For a capacitor with AC voltage source, it is said that the current can be split into a capacitive current component and resistive current. My professor says the displacement and capacitive current is not the same, what is the difference between them?

A resistor, inductor, and capacitor are connected in parallel with a function generator. Calculate the apparent power of the circuit.

Enter your answer in VA but do not enter the unit. Round to the nearest whole VA.

VT = 117V RMS, R = 170Ω, XL = 169Ω, XC = 46Ω

Total: 100marks

General Directions: Answer as Directed

Q1. The peak I/P line voltage for 3 phase bridge rectifier is 400V with a resistive load of 30 ohm. Calculate the followings;

1. O/P rms voltage
2. O/P load current
3. The 6^th and 12^th harmonic order
4. Draw the I/P and O/P waveforms for the circuit

Q2 A three phase full-wave controlled rectifier supply a highly inductive load with R=10Ω. The supply is a 3-phase Y-connected with 208v r.m.s.

Calculate:

1. The load current when the Tyhyristors firing angle α=40⁰.
2. The power drawn from the supply
3. If the current value kept at (a) and α is changed to 135⁰, calculate the power returned to the supply

Difference between SPIC and the microcontroller?

A 3 phase 450V (line-to-line), 1150rpm induction machine has the following equivalent circuit parameters. R1=0.33 Ohms, X1=1.3Ohms R2 = 0.25 Ohms X2 = 40Ohms. Determine the following: a) Rated stator current (per-phase) b) Input power factor c) Total power across the air gap d) The full-load torque e) Magnitude of the starting current

If up to 40% of an engineer's working time spent writing and communicating, why is communication not a more substantial and significant part of an engineering students educational training?

Design and implement a sequential circuit that counts from 0-3 in a repeating cycle with two inputs: step and reset. If the step input is 1 the count progresses to the next value, if 0 you stay at the current value. If the reset input is 1 the count returns to 0, if 0 it has no effect. If both step and reset are 1, reset takes precedence.
Use J-K flip flops in your design and follow the design process outlined:
• Derive a state diagram for the circuit
• Create a state table
• Derive the flip-flop input equations and output equations
• Draw the logic diagram
• Implement the logic circuit on your breadboard for presentation

comparison of class A and class B amplifiers ?