Practice Problems

1. Plot the following equations:

a) \(v(t) = - 2 + 2\cos(360*100\ Hz*t)mV\)

b) \(v(t) = 2\ cos(360*10\ Hz*t)\ V\)

c) \(v(t) = 4\ cos(360*1k\ Hz*t)\ mV\)

d)

What equation is associated with the graph?

e)

What equation is associated with the graph?

f) What equation is associated with the graph (note: the period is 0.01667ms)?

2. If \(v_{s}(t) = 4 + 8\cos{(360*10k*t)\ V}\), graph i~x~(t) for the signal below

3. Find the power consumed by the circuit below given \(V_{S} = 1.5\ V\)

4. Find the average power consumed by the circuit below given

v~s~(t) = 2.12 cos(360° * 100 kHz * t) V

Compare the power consumed by the two circuits above. What can you say about the power consumed?

5. What is \(\frac{1}{Hz}\) equivalent to?

   a. s

   b. 1/s

   c. f

   d. None of the above

6. A 9-V battery is connected to a resistor which consumes 7.22 mW of power. Which of the following AC sources would cause the same resistor to consume 7.22 mW of average power?

   a. 7.22 cos(360° * 2 kHz * t) mV

   b. 9 cos(360° * 2 kHz * t) V

   c. 7.22 mV~RMS~

   d. 9 V~RMS~

7. A B-52 generator produces a signal of v(t) = 290 cos(360° * 400 Hz * t) V.

   a. Graph this signal as a function of time.

b. What is the RMS voltage for the generator above?

8. The fuse for a 2000-pound general purpose bomb includes a spinner which produces an AC signal of v(t) = 15 cos(360° * 2 kHz * t) mV. The arming circuit is modeled as three resistors, as shown below. Graph the current signal coming out of the spinner, I~S~(t).

9. Which of the two sources below produces more average power?

10. The circuit below has a current source providing

\(i(t) = 11.75\cos(360{^\circ}*50\ Hz*t)A\).

Find v~1~(t).

11. An AC-powered electric fan, modeled as a 150-Ω resistor, is to be plugged into a standard 120 V~RMS~ wall outlet. Since the fan requires 90 V~RMS~ to operate, a resistor is added to form a voltage divider.

Radapter

Vs=120VRMS

Rfan=150Ω

Find the resistor value, R, to provide the fan 90 V~RMS~.