Assume that a 50-Hz, 50-kVA, star-delta transformer bank of vector group Yd11 is accidentally paralleled with a 50-Hz, 50-kVA, star-star transformer bank of vector group Yy0. Both have a bank ratio of 2000/200-V. The equivalent impedances referred to the respective secondaries are ZΔ = 0.1106/60.2° Ω and ZY = 0.0369/60.2° Ω. (a) Assuming the load switch to be open, draw the connection diagram   (3.0 marks). (b) Determine the magnitude of the current circulating in each transformer secondary   (15.0 marks). (c) Express the current in (b) as a percent of the rated transformer current for each transformer   (2.0 marks).                                                                                  Use the method of mesh analysis applied to the three-phase circuits (marks will not be awarded for using the single-phase equivalent method). show all your steps

1-what is the best choice of a single phase motor for compressor?
a) a shaded pole motor
b) a split phase motor
c) a capacitor start induction motor
d) a capacitor run induction motor
e) a permanent split capacitor motor

2- Stepper motors typically operate with:
a) A single phase
b) Three phases (X,Y and Z)
c) 4 phases
d) 2 phases ( A and B)
e) The number of phases varies with the motor design

3- A 200 step stepper motor:
a) Has 200 poles
b) Has 100 poles on 2 phases
c) Has 4 poles on each of 2 phases
d) is not commercially available
e) is too complex to manufacture

4- When a stepper motor moves from one step to another:
a) The motor may overshoot
b) There is no possibility of overshoot
c) The overshoot will not exceed 1/2 step
d) A and C but not B
e) All of the above

5- The controller in an industrial servo motor system:
a) Is universal, any controller will work with any motor
b) Is always sold with the motor
c) Must be match to the motor according to manufacturer's recommendation
d) A and B
e) B and C

6- Industrial servo motor:
a) are not capable of holding a fixed position
b) have a holding torque that hold a fixed position with no movement
c) hold a fixed position by making small corrections as the load moves, resulting in small oscillations
d) are better than a stepper motor of holding a fixed position
e) do not have enough torque that hold fixed positions with no movement

7-Limit switches can be used:
a) with stepper or servo systems
b) can be used to prevent machine over travel
c) can be used to automatically set the 0 point for a motor controller
d) B and C
e) A, B and C

8- Stepper motors of the same faceplate sizebut longer length:
a) offer no difference in performance
b) generally run at higher speed
c) are generally capabe of producing more torque
d) generally run at lower speed
e) generally run at longer period of time

9- For an intermittent load, such as a manual lathe, which method should be used to size the motor:

a) The motor’s nominal size should match the minimum load
b) The motor’s nominal size should match the RMS horsepower calculated based on the anticipated loads
c) The motor’s nominal size should match the maximum anticipated load
d) Any available motor can be used, the operator will adapt their work methods

10- A motor is running at 90% of its nameplate voltage. Compared to running under the same condition at 100% of name plate voltage you expect the temperature to:

a) Increase
b) Decrease
c) Remain the same

11- A motor is running at 90% of its nameplate voltage. Compared to running under the same condition at 100% of name plate voltage you expect the current to:
a) Increase
b) Decrease
c) Remain the same

12- A motor is running at 90% of its nameplate voltage. Compared to running under the same condition at 100% of name plate voltage you expect the speed to:
a) Increase
b) Decrease
c) Remain the same

13- A motor is running at 110% of its nameplate voltage. Compared to running under the same condition at 100% of name plate voltage you expect the starting torque to:
a) Increase
b) Decrease
c) Remain the same

14- Motors with the same NEMA frame size are:
a) Electrically interchangeable (identical voltage and current ratings)
b) Mechanically interchangeable (same mounting hole locations and shaft size)
c) Mechanically interchangeable (same speed and horsepower rating)
d) Both electrically and mechanically interchangeable
e) The same colour

15- Which is not a component of a DC motor:
a) Field Winding
b) Squirrel Cage Rotor
c) Armature winding
d) Brushes
e) Commutator

16- In a permanent magnet DC motor the magnets take the place of the:
a) field Winding
b) Armature Winding
c) Bearings

17- If the field coil of a DC shunt motor is opened, the armature speed will __________.
a) increase
b) decrease
c) stay the same
d) runaway
e) stop

18- The __________ DC motor has the highest starting torque.
a)series
b)shunt
c) additive compound
d) subtractive compound
e) long shunt

19- Which of the following factors determine the synchronous speed of an AC motor?
a) inductance of the rotor windings
b)the frequency of the applied voltage
c) the number of field poles per phase
d) the physical load driven by the motor
e) both b and c

20- Which of the following inductance motors use a centrifugal switch?

a) resistance-start, induction-run
b) capacitive-start, induction run
c) shaded pole
d) a and b
e) b and c

Explain how a wireless client is de-authenticated.

In TDM, what do you think are some of the effects of increasing the number channels while holding the sampling rate constant?

An example of a PIC C program code for line following and obstacle avoiding robot? For it move forward and avoid an obstacle? PIC18F86722

4. Cross sectioning

a) Describe briefly the steps involved in a cross-sectioning procedure of an encapsulated sample.

b)Explain the differences between grinding ad polishing.

2, Die deprocessing.

a) Name TWO materials that typically made up the passivation layers.

b) Reactive Ion Etching (RIE) is a type of dry etching which is of plasma-based. With an aid of diagram, explain the mechanism of RIE.

c) Wet etching and dry etching are the most common die deprocessing techniques. Give TWO advantages and disadvantages of wet etching in form of tables.

Q3. Demonstrate the process of executing a nested subroutine, where you will have three subroutines. Subroutine number 2 will be called from subroutine number 1, while subroutine number 3 will be called from subroutine number 2. In Keil uVision, screenshot your result, by showing the value of PC and LR. Discuss your results by relating the values in PC, LR and stack for each subroutine call.

WHAT ARE THE KEY CONCEPTS YOU NEED TO KNOW ABOUT THE IT NETWORK ENGINEERING?

PLEASE GIVE THE CONCEPTS EXPLAINED

PLEASE GIVE SOME GOOD REFERENCES AND BOOKS TO LOOK INTO FOR THE

CompTIA CySA+ - CompTIA IT Certifications

IT FUNDEMENTALS - A+ - Network+ - Security+ , etc.

PLEASE GIVE THE BOOKS OR REFERENCES OR LINKS I COULD USE FOR THE GOOD REFERENCES FOR PREPARING AND STUDYING

Advanced Mechatronics - Frequency Analysis

Question#01: Describe the procedure of determining the correct sampling rate based on spectral analysis.

Question#02: What is the assumption used to apply harmonic analysis to functions (e.g.
sets of measured data) for which the period T is not known or for which the periodicity
itself is questionable?

Question#03: Assume that the vibration data are measured over 2 minutes. The Fourier
analysis is used to determine the frequency spectrum. What is the fundamental frequency
as determined from the discrete Fourier transform algorithm?

Question#04: Explain what is the cut-off frequency of a filter.

calculate built-in potential, maximum electric field and width of the depletion layer in Si p-n diode doped with donors and acceptors to concentration of 2x10^17cm^-3 and 5x10^16 cm^-3 respectively

estimate the maximum voltage which can be safely applied to the diode descibed above

estimate density of reverse current in the diode desribed in top if the diffusion constants and the diffusion lengths of holes and electrons are about 30cm^2/s and 100mm respectively

Below are listed parameters for different direct-mapped cache designs.

Cache Data Size: 32 KiB

Cache Block Size: 2 words

Cache Access Time: 1 cycle

Word: 4 bytes.

Calculate the total number of bits required for the cache listed above, assuming a 32-bit address. Given that total size, find the total size of the closest direct-mapped cache with 16-word blocks of equal size or greater. Explain why the second cache, despite its larger data size, might provide slower performance than the first cache.

Provide an example application that uses normally open relay Contacts and normally closed relay contacts?

in a rectangular wave guide for which a = 1.5cm b=0.8cm o=0,m =m0 and E=4e0 Hz= 2 sin (pi x /a) cos (3piy/b) sin (pi x 10^11 t -bz)a/m. assume TE13 determine of the field components for this mode.