Homework Help for Engineering

1. Design an unregulated power supply that uses a step down transformer and two Silicon diodes.
i. This power supply must be able to deliver an average dc current of 18,92mA to a load 
having a resistance of 1000.
ii. The supply to the primary of the transformer is 220V (RMS) at 50Hz.
iii. Show all calculations.
iv. HINT:- (1) Draw the circuit diagram first.
a. (2) Take the forward voltdrop of the diodes to be 0,7 volts.
(15)
1.1 Draw a neatly labelled diagram of the voltage output waveform that occurs across RL, as 
would be displayed by an oscilloscope that has been set up to display two full cycles.
v. Indicate the peak value and the time span of one cycle. (5)
1.2 Draw a simple circuit diagram that shows how an LED and a photo diode may be used to 
count the number of bottles passing a point on a conveyor belt.
1.3 Explain the operation of the circuit.

An unregulated center-tap full wave rectifier, with load resistor = 10K, is supplied with 
220Vrms at 50Hz to the transformer primary.

The following questions are relevant to the above description.
8.1 Draw the described circuit diagram. (3)

8.2 If the dc current drawn by the load resistor is 0,9667 mA, calculate the turns ratio of the 
transformer. (11)

8.3 What should the minimum PIV of the diodes be? (2)

8.4 Draw a graph (on the display answer sheet provided) of two complete cycles of the input 
voltage waveform, that would be measured by an oscilloscope, across the entire 
transformer secondary of the circuit. Indicate the peak voltage levels as well as the 
period. (4)

8.5 Directly next to the graph of question 2.4, draw a graph of two cycles of the output 
waveform as would be measured by an oscilloscope across the load resistor. Indicate 
the peak voltage levels as well as the period. (4)

8.6 Again directly beneath the graph of question 2.4, draw a graph of two cycles of the 
output voltage waveform as would be measured by an oscilloscope across the load 
resistor if one of the diodes has gone open circuit.

i) What is the factor affecting the permeability of soil mass? 
ii) The soil layers below have a cross section of 100 mm x 100mm each. The permeability 
of each soil is: kA = 10-2
cm/sec, kB = 3x10-3
cm/sec; kC = 4.9x10-4
cm/sec. Find the rate 
of water supply in cm3
/hr.
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b. If all elements are resistors in such a way that element A has resistance  

    has and similarly for all elements. What would be the value of the equivalent resistance in terms of and  

1. What are the elements in series?

Elements A and C are in series, also elements I and K

Two random samples of sizes 8 and 10 are drawn from two normally distributed populations having variances 20 and 36, respectively. Find the probability that the variance of one sample is more than twice the variance of other sample.

A two dimensional variable (X, Y) is uniformly distributed over the square having the vertices (2, 0), (0, 2), (-2, 0), and (0, -2).

Find:

(i) Find the joint probability density function.

(ii) Find associated marginal and conditional distributions.

(iii) Find E(X), E(Y), Var(X), Var(Y).

(iv) Find E(Y|X) and E(X|Y).

(v) Coefficient of correlation between X and Y.

The mean lifetime of a sample of 100 fluorescent light bulbs produced by a company is computed to be 1570 hours with a standard deviation of 120 hours. If μ is the mean lifetime of all the bulbs produced by the company, test the hypothesis μ = 1600 hours against the alternative hypothesis μ ≠ 1600 hours. Use a significance level of 0.05 and find the P value of the test.

How do you bog in medical engineering?

Show me the development of Fe-Fe2C phase diagram.

Show me the development of microstructure on Fe-Fe2C phase diagram.

During a flow of 500 liters, the gage pressure is 68 kPa in the horizontal 300 mm supply line of a water turbine. A 41 kPa vacuum is measured at a 450 mm section of draft tube 2 m below the turbine. Assuming an efficiency of 85%,

a. Compute the total head extracted by the turbine.

b. Compute the output horsepower of the turbine.

c. Compute the input horsepower of the turbine.

Describe how rock are blasted using explosive

3. One pound of liquid water is at its boiling point of 575oF. It is then heated at constant pressure to 650oF, and then compressed at constant temperature to one-half of its volume (at 650°F), and finally returns to its original state of the boiling point at 575°F. Calculate AH and AV for the overall process

What is avg power loss for a signal travelling from Earth station to GSO satellite?