Quiz on Chapter 24 Flashcards
. How do the resistance, capacitive reactance, and inductive reactance change when the frequency in a circuit is increased?
In an a.c. circuit, an inductor produces inductive reactance which causes the current to lag the voltage by 90 degrees. Because the inductor “reacts” to a changing current, it is known as a reactivecomponent. The opposition that an inductor presents to a.c. is called inductive reactance (XL). This opposition is caused by the inductor “reacting” to the changing current of the a.c. source. Both the inductance and the frequency determine the magnitude of this reactance. This relationship is stated by the formula:
A 3.33-kOhm resistor is connected to a generator with a maximum voltage of 141V. Find (a) the average and b. the maximum power delivered to this circuit.
The reactance of a capacitor is 65ohms at a frequency of 57Hz. What is its capacitance?
Find the impedance of a 60Hz circuit with a 45 Ohm resistor connected in series with a 95 uF capacitor.
Predict/Explain When a long copper wire of finite resistance is connected to an ac generator, as shown in figure (a), a certain amount of current flows through the wire. The wire is now wound into a coil of many loops and reconnected to the generator, as indicated in Figure. (a) Is the current supplied,to the coil greater than, less than, or the same as the supplied to the uncoiled wire? (b) Choose the best explanation from among the following.
I. More current flows in the circuit because the coiled wire is an inductor and inductors tend to keep the current flowing in an ac circuit
II. The current supplied to the circuit is the same because the wire is the same. Simply wrapping the wire in a coil changes nothing.
III. Less current is supplied to the circuit because the coiled wire acts as an inductor, which increases the impedance of the circuit.
III. Less current is supplied to the circuit because the coiled wire acts as an inductor, which increases the impedance of the circuit.
An inductor, also called a coil, choke or reactor, is a passive two-terminal electrical component which resists changes in electric current passing through it.
Find the frequency at which a 33 uF capacitor has the same reactance as a 33mH inductor. What is the the resonance frequency of an LC circuit made with this inductor and capacitor?
Two RLC circuits have different values of L and C. Is it possible for these two circuits to have the same resonance frequency? Explain.
The resonant frequency of RLC circuit is 1/2piSqrt(L*C)
If the product L*C is same for the two circuits in question then you can have the same resonant frequency for eg the circit with 6H inductance and 1F capacitance will have same resonant frequency as 3H inductance and 2F capacitance
