CHAPTER 14. ELECTRONICS 14.3
Z =
√
X^2 + R^2 =
�
53 , 052 + 30^2 = 60,9 Ω
Exercise 14 - 1
- Why is the instantaneous value ofVIof little use in an AC circuit containing an
inductor or capacitor? - How is the reactanceof an inductor differentto the reactance of a capacitor?
- Why can the ratio ofthe maximum voltage tothe maximum current ina circuit
with a resistor and an inductor not be called a reactance? - An engineer can describe a motor as equivalent to a 30 Ω resistor in series with
a 30 mH inductor. If themaximum value of the supply voltage is 350 V,what is
the maximum current? Assume that the frequency is 50 Hz. - A timer circuit in a factory contains a 200 μF capacitor in series with a 10 kΩ
resistor. What is its impedance? Assume that thefrequency is 50 Hz. - A 3 mH inductor is connected in series witha 100 μF capacitor. The reactance
of the combination is zero. What is the frequency of the alternating current?
More practice video solutions or help at http://www.everythingscience.co.za(1.) 01j5 (2.) 01j6 (3.) 01j7 (4.) 01j8 (5.) 01j9 (6.) 01ja14.3 Filters and Signal Tuning ESCGC
Capacitors and Inductors as Filters ESCGD
We have already seen how capacitors and inductors pass current more easily at certain
frequencies than others. To recap: if we examine the equation for thereactance of
a capacitor, we see that the frequency is in the denominator. Therefore, when the
frequency is low, the capacitive reactance is very high. This is why a capacitor blocks