Electrical Engineering Answers

1. (i) Using npn BJTs, with a dc current gain of 200 and an Early Voltage of 100 V, design a current source of magnitude 2 mA. Determine the voltage compliance of your current source.

(ii) Use this current source to establish a common emitter amplifier, employing an active load, using pnp transistors, with VA = 50 V. If you are provided with power supplies of + 5 V, determine the gain of your amplifier. Determine the maximum input voltage than can be applied to this amplifier.

 With the help of an appropriate circuit diagram, describe the wiring of a DC series motors and DC shunt motors.

On Xilinx, design a logic circuit to implement the four functions, F1 – F4 described below, simultaneously using one `157 IC. Construct your entire schematic diagram and label all necessary pins and simulate for results.

F1 = a’b, F2 = a + b’, F3 = a xnor b, F4 = b’

please just do an explanation of how you did it from the beginning to end, basically an explanation on how you did it on xilinx.

What is ramp function

A DC shunt motor is rated 5kW at 125V. When the armature is held stationary, a voltage of 5V applied to the terminals will cause a full load current of 40A to flow through the armature.

(a) Determine the armature current if rated voltage is applied directly across the motor terminals.

(b) Determine the value of the external resistance that must be connected in series with the armature in order to limit the starting current twice that of the rated armature current. 

1.Determine the reactions at A and B when (a) α = 0, (b) α = 90°, 

(c) α = 30°.

The voltage applied to a purely inductive coil of self inductance 16.5mh is given by the equation v=150sin314t+125sin942t+100sin1570t

a) List four types of secondary seals used with rotary mechanical seals?

b) List two advantages mechanical seals have compared to gland packing?

The ohmmeter circuit in fiq has EB =1•5v ,R1=15kohm,Rm=50ohm,R2=50ohm and meter FSD =50uA.Determine the ohmmeter scale reading ar 0.5FSD and determine the new resistance value that R2 must be adjusted to when EB falls to 1.3v also recalculate the value of Rx at 0.5 FSD when EB=1.3v

A si pn junction ( Na= 1016 cm-4 and Nd = 4 × 10 16 cm-3) is biased with Va= -3v . Calculate the built-in potential and depletion layer width ?