Electrical Engineering Answers

A 228/-30 volt constant potential generator delivers load to an impedance. Assuming the reactance only to be variable and the line impedance is (6 + j4.5) ohms, calculate for maximum power transfer: a) the load impedance, b) the current, and c) the load power and power factor.

An impedance coil whose resistance and inductance are 18 ohms and 3.82 mH, respectively, is connected in parallel with a series combination of a 5.3 uF capacitor and a variable resistor. For what value of resistance will the circuit be in resonance at 1000 cps?

A 7.5 HP 230 volt three phase motor takes a line current of 18.4 A when operating at

rated output at an efficiency of 88%. Calculate the indications on wattmeters when

these are inserted to measure power (a) by two wattmeter method, (b) by the artificial

neutral method and (c) by the T method.

When a voltage of 100 volts at 50 Hz is applied to a series connection of a resistor A

and an inductor A, the current taken is 8 A and the power is 120 watts. When applied

to another series connection of a resistor B and an inductor B, the current is 10 A and

the power is 500 watts. What current and power will be taken when 100 V is applied

to the two coils in series?

A coil is wound with 300 turns over a stee ring of relative permeability 900 having a mean circumference of 400 mm and a cross-sectional area of 500 mm2 . If the coil has a resistance of 8Ω and is connected across a 20V dc supply, using a neat sketch, calculate:

a).The coil magneto-motive force

b).The magnetic field strength

c).The total flux

d).The reluctance of the ring

e).The permeance of the ring and

f).The flux density in the ring

A coil is wound with 300 turns over a stee ring of relative permeability 900 having a mean circumference of 400 mm and a cross-sectional area of 500 mm2 . If the coil has a resistance of 8Ω and is connected across a 20V dc supply, using a neat sketch, calculate:

a).The coil magneto-motive force

b).The magnetic field strength

c).The total flux

d).The reluctance of the ring

e).The permeance of the ring and

f).The flux density in the ring

Develop a double layer winding diagram having: S=48, P= 8 and m=3

Develop a double layer winding diagram having: S=48, P= 8 and m=3

4. Develop a double layer winding diagram having: S=48, P= 8 and m=3

Luke Autbeloe drops a pile of roof shingles from the top of a roof located 8.52 meters above the ground. Determine the time required for the shingles to reach the ground.