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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 ?
Design a system called a parallel binary comparator, that compares the 4 – bit binary string A to the 4 – bit binary string B. If the strings are exactly equal, provide a HIGH – level output to drive a warning buzzer.
Write the Boolean logic Equation and draw the logic circuit along with its truth table that represents the following statement:
“A bank burglar alarm (A) is to activate if it is after bank hours (H) and the front door (F) is opened or if it is after banking hours (H) and the vault door is opened (V)”.
A capacitive level sensor has the dimensions and properties shown below. What is the capacitance C in picofarads at the liquid level shown? Type in a one-decimal number
H = 4.0 meters
h = 3.9 meters
a = 1.0 millimeters
b = 6.0 millimeters
ε = 8.8542 x 10 picofarads/meter
k = 78.5
2. Box 1, a wooden box, has a mass of 8.60 kg
and a coefficient of kinetic friction with the
inclined plane of 0.35. Box 2, a cardboard box,
sits on top of box 1. It has a mass of 1.30 kg.
The coefficient of kinetic friction between the
two boxes is 0.45. The two boxes are linked by
a rope which passes over a pulley at the top of
the incline, as shown in the diagram. The inclined plane is at an angle of 38.0° with respect to thehorizontal.
(a) What is the acceleration of each box? (7 marks)
(b) Now consider all surfaces are frictionless. Then calculate the amount of force with direction
to prevent the sliding of the boxes. (3 marks)
