A resistor and capacitor are connected in series across an ac generator. The voltage of the generator is given by V ( t ) = V 0 cos ( ω t ) , where V 0 = 120 V , ω = 120 π rad / s , R = 700 Ω , and C = 3 μ F . (a) What is the magnitude of the impedance of the R C circuit? (b) What is the amplitude of the current through the resistor? (c) What is the phase difference between the voltage and current?

Respuesta :

Answer:

a.1127.7Ω

b.0.1714A

c.[tex]0.9^{0}[/tex]

Explanation:

From our knowledge of AC Circuit, where we have the resistor arranges in series with the capacitor, the total impedance(Z) of the circuit is given as

[tex]Z=\sqrt{R^{2}+X_{C} ^{2}}\\[/tex]

Where R is the resistor value in the circuit and [tex]X_{C}[/tex]  is the circuit capacitance due to the capacitor in the circuit and is express as

[tex]X_{C}=\frac{1}{WC}\\[/tex]

By inserting values, we can determine the value of the capacitance

[tex]X_{C}=\frac{1}{120\pi *3*10^{-6}}\\X_{C}=884.19\\[/tex]

since the resistor  value is 700Ω, we can substitute into the equation for the impedance

[tex]Z=\sqrt{700^{2}+884.19 ^{2}}\\Z=1127.7ohms\\[/tex]

b. from the expression of Ohms law, [tex]V=IR[/tex]

the voltage in this case is the amplitude of the voltage in the question i.e 120v

Hence  [tex]I_{R}=120/700\\ I_{R}=0.1714A\\[/tex]

C. the phasor angle is express as

[tex]tan\alpha=\frac{X_{C} }{R}[/tex]

[tex]tan\alpha=\frac{884.19 }{700}\\tan\alpha=1.263\\\alpha=tan^{-1}(1.263)\\\alpha =0.90\\[/tex]

Answer:

a) 1127.7ohms

b) 0.1714A

C) 0.90°

Explanation:

From the AC Circuit where resistor and capacitor are arrange in series

Z=√(R)²+(XC)², Where R= resistor, Xc= Capacitance, also Xc=1/Wc

Therefore Xc= 1/120π×3×10⁻6, ∴ Xc= 884.19

Using  Resistor R= 700ohms

Impedance Z= √(700)²+(884.19)² = 1127.7ohms

b) Using V=IR, and Voltage V= 120V

Hence Current I=V/R= 120/700= 0.1714A

c) The phase angle is express as TanФ=Xc/R =884.19/700= 1.263

Ф=Tan⁻⁽1.263⁾ =0.90°