why differential signal cancels inductance?

thanks

An inductor in a switch-mode power supply that operates at a peak current of 8 A needs to store 80 mJ of energy, thereafter release it to a 10 ? load resistor. Suppose this inductor had to be custom designed and built as a solenoid coil wound on a pencil (10 mm diameter) with no magnetic properties. Only one layer of turns is allowed on the pencil’s outer surface, and 0.1-mm diameter enamel coated wire has to be used. Answer the following carefully:

(a) Calculate the required inductance to store the energy.

(b) Draw an isometric sketch of the air-core inductor with only one layer of turns, showing its dimensions and a few turns of wire. Also draw some flux lines.

(c) Calculate the effective cross-sectional flux area of the air-core inductor.

(d) Do 3 iterative calculations to solve the number of turns (tightly wound next to each other) required to achieve the inductance in (a). Comment on your result after each iteration.

Define the following terms related to D/A converter;                                  

            (i) resolution   (ii) accuracy    (iii) settling time         (iv) offset error      (v) gain error

What is the high voltage and insulation tests for transformers ? How we can generate full-wave ,chopped-wave and switching wave voltages in Marx generator for (Lightning and switching impulse tests )?

Butterworth filter

a)Design a 5th order low pass Butterworth low-pass filter with a cut-off frequency of 1592 Hz and a dc gain of 3dB. Find and present the mathematical transfer function of the filter, showing all your steps.

b) Write a Matlab code to plot the magnitude of this function with a linear scale in dB units on the ordinate, and a log scale of frequency on the abscissa.
The plot range should be: ordinate- linear scale from -100dB to +10dB; abscissa- log scale from 1000 rads/sec to 100,000 radians/sec.

For a company that is obliged to employ an electrical and electronic engineer, I would like you to make a risk assessment and include the following topics.

STEP 1: Detect hazards

STEP 2: Identify Risks

STEP 3: Decide on control measures

STEP 4: Complete control measures

STEP 5: Watch and repeat

QUESTION 16

in 1000 words discus the campus’ load profile?

based on the given information or Context below,

Context:

Mookodi Enterprise is a business consultancy with 543 employees. They are based in the north of Johannesburg on a 10Ha campus. Mookodi connects to the national grid at 11kV and pays a seasonal industrial low voltage (LV) tariff of 141.67 cents in summer and 165.94 cents in winter. Thirty percent of Mookodi’s employees are based at their clients’ offices and are not permanently based on the campus.

The campus has the following buildings:

• Canteen (Purple)
• Welcome Centre, Gym and Conference Centre (Green)
• Guardhouse (Light blue)
• Main Office Building 1 (Maroon)
• Main Office Building 2 (Dark blue)

Below is the campus’ electricity consumption over the last year:

i. Explain how to evaluate the correct combination of RL and CL for appropriate filter efficiency. ii. Suggest three (3) alternative designs if the output voltage is to be used to drive electronics with various input voltages. (V

Match the following concepts related to optical switches.

Brief discuss the operation of a split phase single phase single induction motor with respect to its construction, current relationship and torque characteristics. Illustrate your answer by means of diagram

A 400V, 2 pole, 50 Hz, three-phase induction motor is drawing 60 A at 0.85 PF lagging. The stator copper losses are 2 kW, the stator core losses are 1.8 kW and rotor copper losses are 700 W. The friction and windage losses are 600 W, the stray loss 100 W, and rotor core loss 100 W.
Find the following quantities:
a. The air gap power.
b. The developed mechanical power.
c. The output power.
d. The efficiency of the motor.
e. The rotor speed when the slip is 2 %. Sketch the power flow diagram and enter all data.

For 345 KV, a three conductor per phase are to be used at 0.30 meters per conductor in a flat horizontal layout. The distance between the centers of each bundle is 4 meters in a delta configuration. GMR for the conductors is 0.012 m

Find:

GMD, L, and XL

Why proper lighting is important and why lumen method is very useful for a effective buildings.Besides ,how can this lumen method help in terms of the uses.

SUBJECT: MECHANICAL AND ELECTRICAL SYSTEMS