A 120Ω resistor is in parallel with a capacitor with a capacitive reactance of 40 Ω. Both components are across a 12 V ac source. What is the magnitude of the total impedance? 37.9Ω 14400Ω 3.7Ω 4800Ω TRUE ANSWER : ? YOUR ANSWER : ?
What is the angular difference between +j4 and –j4? 180° 270° 30° 90° TRUE ANSWER : ? YOUR ANSWER : ?
When the frequency of the voltage applied to a series RC circuit is decreased, the impedance doubles remains the same decreases increases TRUE ANSWER : ? YOUR ANSWER : ?
When the frequency of the voltage applied to a series RC circuit is increased, the phase angle decreases becomes erratic remains the same increases TRUE ANSWER : ? YOUR ANSWER : ?
An ac circuit consists of a resistor and a capacitor. To increase the phase angle above 45°, the following condition must exist: R > XC R < XC R = XC R = 5XC TRUE ANSWER : ? YOUR ANSWER : ?
The voltages in Problem 4 are measured at a certain frequency. To make the capacitor voltage greater than the resistor voltage, the frequency must be increased is held constant must be decreased has no effect TRUE ANSWER : ? YOUR ANSWER : ?
A 47Ω resistor and a capacitor with 150Ω of capacitive reactance are in series across an ac source. The impedance, expressed in rectangular form, is Z = 103Ω Z = 47Ω + j150Ω Z = 47Ω – j150Ω Z = 197Ω TRUE ANSWER : ? YOUR ANSWER : ?
When the frequency of the source voltage decreases, the impedance of a parallel RC circuit decreases does not change decreases to zero increases TRUE ANSWER : ? YOUR ANSWER : ?
A capacitor with 150Ω of capacitive reactance is across an ac source. The impedance, expressed in polar form, is Z = 150 angle 180° Ω Z = 150 Z = 150 –90° Ω Z = 150 angle – 90° Ω TRUE ANSWER : ? YOUR ANSWER : ?
In the complex plane, the number 14 – j5 is located in the first quadrant second quadrant third quadrant fourth quadrant TRUE ANSWER : ? YOUR ANSWER : ?