Electrical and Computer Engineering Homework Solutions

Laplace transform for an RC circuit

Show how to find the Laplace transform of the current indicated as i(t)? See attached file for full problem description.

Phasor Techniques

Using phasor techniques, solve for i in the circuit shown in Figure P4.53 (see attached file).

Mesh Current Analysis

Using mesh current analysis, determine the currents i1(t) and i2(t) in the circuit shown in Figure P4.57 (see attached file).

Impedance

In the circuit shown in Figure P6.9 (in the attached file), if L = 190 mH R1 = 2.3 kΩ R2 = 1.1 kΩ C = 55 nF a) Determine how the input impedance behaves at extremely high or low frequencies. b) Find an expression for the input impedance in the form (see attached file) c) Determine the four frequencies at which ...continues

Filters

Are the filters shown in Figure P6.50 low-pass, high-pass, bandpass, or bandstop (notch) filters? Please see both attached files for filters.

Power Factor

Determine C so that the plant power factor of Figure P7.25 (see attached file) is corrected to 1 (or the power factor angle to zero) so that Is is minimized and in phase with Vo. vs(t) = 450cos(wt) V w = 377 rad/s Z = 7 < 0.175 Ω

Power

If the voltage and current supplied to a circuit or load by a source are: Vs = 170<(-0.157) V Is = 13<0.28 A determine a) The power supplied by the source which is dissipated as heat or work in the circuit (load). b) The power stored in reactive components in the circuit (load). c) The power factor angle and power facto ...continues

Steady State Circuit

For t > 0, determine for what value of t, i = 6 A in the circuit of Figure P5.71 (attached file) if the circuit is in steady state at t = 0-.

Voltage Across Capacitor

Determine vc(t) for t > 0. The voltage across the capacitor in Figure P5.32 (attached file) just before the switch is changed as shown in the attached file. vc(0-) = -7 V Io = 17 mA C = 0.55 μF R1 = 7 kΩ R2 = 3.3 kΩ

Reactance

a) Calculate the capacitive reactance XC, with C= 1μF and R= 200 Ohms for various frequencies and tabulate the values in Table 1 (see attached file). b) Plot f vs XC and comment on the plot. Compare this plot with another plot of f vs R. c) Calculate the phase angle (θ) for the RC circuit with C = 1μF and R= ...continues

Browse