Electronics - Capacitors - Discussion

5. 

What is the angle theta value for a 5.6 F capacitor and a 50-ohm resistor in series with a 1.1 kHz, 5 Vac source?

[A]. 27.3 degrees
[B]. 62.7 degrees
[C]. –27.3 degrees
[D]. –62.7 degrees

Answer: Option C

Explanation:

No answer description available for this question.

Nagashree said: (May 23, 2011)  
We know tthat cos(angle)=Xc/R

Xc=(1/2*pi*f*c)

By substituting values will get cos(angle)=0.355

So angle=27.3

But in capacitor power factor is lagging so ans is -27.3

Girish said: (Aug 11, 2011)  
That is tanθ =(Xc/R)

MUKUL MISHRA said: (Sep 8, 2011)  
z= R+X
X=1/j*2*pi*f*c = -j*25.83
SO, z= R-j(1/2*pi*f*c) = 50-j*25.83

tan(angle)= img. part/ real part
= -25.83/50
angle = -27.32 degrees

Visakh said: (Oct 6, 2011)  
For RC circuit, tan θ = -Xc/R
Xc=1/(2*3.14*(1.1*10^3)*(5.6*10^-6) =0.0258*10^3
also we have R=50 ohm

=> tan θ= -0.516
θ = tan-1 (-0.516)= -27.29 or -27.3

Makkkk said: (Apr 29, 2013)  
What is power factor here give its importance?

Krishnaa said: (Aug 1, 2013)  
Power factor is the ratio of True power to the Volt-Ampere power.

When the circuit is pure resistive: true power = VA power.

With reactance : Reactive power comes into picture (VA power increases).

Which means impact of reactance in the circuit. This factor of increase in the Power is determined with concept of power factor.

In pure Resistive circuits: V and I are in same phase.

With Reactance : Phase lead/lag occurs (phase difference).

So, cosine of phase difference (cos°) which is literally equivalent to R/Z from co ordinate system (real and imaginary axis).

Aswathi Ms said: (Feb 2, 2014)  
Incase of voltage and current which one lead inductor or capacitor.

Waqar Asmat said: (Apr 13, 2014)  
In capacitor : Current lead the voltage by 90.

In Inductor: Voltage leads the current by 90.

Israr Bagoro said: (Jun 28, 2014)  
In capacitor lead the voltage by 90 degree in inductor voltage lead the current by 90.

Vinayak Birje said: (Aug 17, 2014)  
Theata = tan-1(1/wrc).
So Ans = 27.3 degree.

Sign is +ve because:
Current leads the voltage by 90 degree.

Ravi said: (Jan 2, 2015)  
Z = R+jX, so tanθ = X/R X = 1/2PIfc place the given values in following equation.

Chandru said: (Dec 3, 2015)  
How to calculate this without a calculator?

Abulkalam Ajath said: (Dec 20, 2015)  
There is no chance to calculate without a calculator.

Sandy said: (Sep 18, 2017)  
Please explain in detail.

KIRAN V said: (Sep 18, 2020)  
Given: f = 1.1 kHz; VAC = 5V; R = 50Ω ; C = 5.6μ F.

XC = 1/ (2 * π * F * C).
XC = 1 / (2 * 3.14 * 1.1 * 103 * 5.6 * 10-6)
XC = 1 / 38.6848 * 10-3,
XC = 0.02584 * 10-3,
XC = 25.84.

The phase angle between the current and voltage is calculated from the impedance triangle above as:

For RC Circuit; tan (θ) = XC / R,
(θ) = tan-1 (XC / R),
(θ) = tan-1 (25.84/50),
(θ) = tan-1 (0.5168).

(θ) = 30.02˚.

Syed Shakeeb said: (Feb 17, 2022)  
@Kiran

Don't divide (XC/R) and calculate phase angle.

Calculate directly using (θ) = tan-1 (-XC / R).
You will get (θ) = -27.32˚.

Post your comments here:

Name *:

Email   : (optional)

» Your comments will be displayed only after manual approval.