Electrical Engineering Answers

what makes the magnetic field in a motor rotate?

The differential equation for a control system is given as follows;

d3c/dt3 + 8d2c/dt2+ 31dc/dt + 48c = d2r/dt2 + 4dr/dt +25r

Determine the following, showing ALL relevant steps

a) The corresponding transfer function in its factorized form

b) Normalized transfer function

c) Magnitude slope plot

d) Phase slope plot

Pure resistive of 15 'in 220V-50Hz network, 45º excitation angle

1 phase phase angle controlled AC chopper feeding the load,

a) Draw the circuit diagram exactly, check the current and voltage directions

show on it.

b) Draw the basic waveforms of the circuit with its values.

c) Calculate the basic parameters according to the drawn waveforms.

AC chopper with 1-phase on-off control, which feeds a pure resistive load of 5, in 220V-50Hz network, with 10 Hz- 50% effective period.

a) Draw the circuit diagram exactly, check the current and voltage directions

show on it.

b) Draw the basic waveforms of the circuit with its values.

c) Calculate the basic parameters according to the drawn waveforms.

Describe the uses of Vector Calculus in real life and in Engineering field (any five)

An unbalanced four wire star connected load has a balanced voltage of 400v. The load are Z1= 4+j8, Z2= 3+j4, Z3= 15+j20 ohms.

A.) Find the line current

B.) Find the neutral current

A single phase overhead transmission line delivers 4000 kW at 11 kV at 0·8 p.f. lagging. If resistance and reactance per conductor are 0·15 Ω and 0·02 Ω respectively, calculate:

(i) percentage regulation

(ii) sending end power factor

(iii) line losses

 A single phase overhead transmission line delivers 4000 kW at 11 kV at 0·8 p.f. lagging. If resistance and reactance per conductor are 0·15 Ω and 0·02 Ω respectively, calculate

: (i) percentage regulation

(ii) sending end power factor

(iii) line losses 

An unbalanced four wire star connected load has a balanced voltage of 400v. The load are Z1= 4+j8, Z2= 3+j4, Z3= 15+j20 ohms.

A.) Find the line current

B.) Find the neutral current

 A single-phase overhead transmission line delivers 4000 kW at 11 kV at 0·8 p.f. lagging. If resistance and reactance per conductor are 0·15 Ω and 0·02 Ω respectively, calculate

: (i) percentage regulation

(ii) sending end power factor

(iii) line losses