1. For the circuit given in FIGURE 1 the power factor is 0.72 lagging and the power dissipated is 375 W.

FIG. 1 (see attachment)

Determine the:

(i) apparent power

(ii) reactive power

(iii) the magnitude of the current flowing in the circuit

(iv) the value of the impedance Z and state whether READ MORE »

The supply current was sampled 1024 times over a very short time interval. The data so obtained is given in column B of the accompanying Excel worksheet (see attached).

This worksheet has been set up to give a graph showing the spectral components of the data.

Question 3

i) Obtain the Fourier READ MORE »

An a.c. voltage, V, comprises of a fundamental voltage of 100 V rms at a frequency of 120 Hz, a 3rd harmonic which is 20% of the fundamental, a 5th harmonic which is 10% of the fundamental and at a phase angle of 1.2 radians lagging.

(i) Write down an expression for the voltage waveform.

(ii) Sk READ MORE »

Please give a full and simplified answer to all parts of question 6 to aid me with revision.

When a force F is applied across the face of the crystal, the current is generated. The interconnecting cable can be represented by a lumped capacitance CC. The input resistance of the amplifier, RL, acts READ MORE »

For the waveform shown in attached figure, estimate

(a) the damping factor,

(b) the forced or damped frequency of oscillation, and

(c) the natural or undamped frequency.