A 2 k resistor is in series with a 0.015 F capacitor across a 15 kHz ac source. What is the magnitude of the total impedance and the phase angle? 73.4 and θ = –19.5° 734 and θ = –38.9° 2121 and θ = –19.5° 707 and θ = –19.5° TRUE ANSWER : ? YOUR ANSWER : ?
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? 3.7Ω 4800Ω 14400Ω 37.9Ω TRUE ANSWER : ? YOUR ANSWER : ?
The complex number 6 + j6 is equivalent to 8.4890° 3645° 8.4845° 645° TRUE ANSWER : ? YOUR ANSWER : ?
A 12 kΩ resistor is in series with a 0.02 μF capacitor across a 1.2 kHz ac source. If the current is expressed in polar form as I = 0.3 angle 0° mA, what is the source voltage expressed in polar form? 4.11 V 45.6 V 411.3 V 0.411 V TRUE ANSWER : ? YOUR ANSWER : ?
What is the value of the hypotenuse of a right triangle whose sides are 12 and 18? 2.16 21.63 4.24 3.46 TRUE ANSWER : ? YOUR ANSWER : ?
A 2 kΩ resistor and a 0.002 μF capacitor are in series across an ac source. Current in the circuit is 6.50 mA. The true power is 130 mW 845 mW 84.5 mW 13 mW 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 Z = 150 angle 180° Ω Z = 150 –90° Ω Z = 150 angle – 90° Ω TRUE ANSWER : ? YOUR ANSWER : ?
When the frequency of the source voltage decreases, the impedance of a parallel RC circuit increases does not change decreases decreases to zero 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 = 5XC R < XC TRUE ANSWER : ? YOUR ANSWER : ?
A 470 resistor and a 0.2 F capacitor are in parallel across a 2.5 kHz ac source. The admittance, Y, in rectangular form, is 212 318.3 3.14 mS + j2.12 mS 2.12 mS + j3.14 mS TRUE ANSWER : ? YOUR ANSWER : ?