An ac voltmeter, which displays the rms voltage between the two points touched b

Question

An ac voltmeter, which displays the rms voltage between the two points touched by its leads, is used to measure voltages in the circuit shown in the figure(Figure 1) .

In this circuit, the ac generator has an rms voltage of 7.60 V and a frequency of 25.0 kHz . The inductance in the circuit is 0.250 mH , the capacitance is 0.150 F , and the resistance is 3.50 .

Part A

What is the reading on a voltmeter when it is connected to points A and B?

Express your answer using two significant figures.

Vrms = V

Part B

What is the reading on a voltmeter when it is connected to points B and C?

Express your answer using two significant figures.

Vrms = V

Part C

What is the reading on a voltmeter when it is connected to points A and C?

Express your answer using two significant figures.

Vrms = V

Part D

What is the reading on a voltmeter when it is connected to points A and D?

Express your answer using two significant figures.

Vrms = V

Explanation / Answer

Here, inductive reactance

XL =2pifL=2pi*25*10^3*0.25*10^-3

XL = 39.25 ohms

And capacitive reactance

Xc=1/2pifC=1/2pi*25*10^3*0.15*10^-6

Xc = 42.46 ohms

So, impedance

Z=sqrt[R^2+(XL-Xc)^2]

Z=sqrt[3.5^2+(39.25 - 42.46)^2]

Z = 4.75 ohms

So, total current

Irms =Vrms/Z = 7.60/4.75 =1.6 A

Part A:

Vab =IXL =1.6*39.25

Vab = 62.80 V

Part B:

Vbc =IXC =1.6*42.46

Vbc = 67.94 V

Part C:

Vac =I(XL-Xc) =1.6*(39.25 - 42.46)

Vac = - 5.14 V

Part D:

Vad =IZ =1.6*4.75

Vad = 7.60 V

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.