Inductive and Capacitive Reactances - AC circuits

In summary, the question asked about the effect of increasing driving frequency on amplitude for a circuit with a purely capacitive load (Vc and Ic) and a purely inductive load (VL and IL). The relevant equations for capacitive and inductive reactance were provided to help find the expressions for voltage and current. The question also referenced a related post on a physics forum.
  • #1
uzair_ha91
92
0
Question:
If we increase the driving frequency in a circuit with a purely capacitive load, do (A) amplitude Vc and (B) amplitude Ic increase, decrease or remain the same?
If instead the circuit has a purely inductive load, do (C) amplitude V L and (D) amplitude I L increase, decrease or remain the same?
Relevant Equations:
Xc= 1/wC = V/I
X L= wL = V/I
Attempt at solution:
I don't understand how to apply there equations here to get the answer...So please tell me how to find the answer here... And also can you tell me whether there is a link between this question and this https://www.physicsforums.com/showthread.php?t=333786&goto=newpost (which i recently posted) ?
 
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  • #2
let's re-simplify some things:

Inductance (you can assume this is as resistance for the time) of a capacitor XC=1/(2πfC)

For an inductor XL=2πfL

Can you find expressions for the Voltage and current through the capacitor and inductor?
 
  • #3
Vc= Ic x Xc
V L=I L x X L
 
  • #4
rock.freak667 said:
let's re-simplify some things:

Inductance (you can assume this is as resistance for the time) of a capacitor XC=1/(2πfC)

For an inductor XL=2πfL

Can you find expressions for the Voltage and current through the capacitor and inductor?

Small typo -- you meant "reactance" instead of "inductance"... (if you want to fix it, I'll just delete this post of mine to clean up)
 

1. What is the difference between inductive and capacitive reactance?

Inductive reactance is the opposition to the change in current flow caused by an inductor in an AC circuit, while capacitive reactance is the opposition to the change in current flow caused by a capacitor in an AC circuit.

2. How do inductive and capacitive reactance affect AC circuits?

Both inductive and capacitive reactance can cause a phase shift in AC circuits, which can affect the overall behavior of the circuit. Inductive reactance leads to a lagging current and capacitive reactance leads to a leading current.

3. How are inductive and capacitive reactance calculated?

Inductive reactance is calculated using the formula XL = 2πfL, where f is the frequency of the AC current and L is the inductance of the inductor. Capacitive reactance is calculated using the formula XC = 1/(2πfC), where f is the frequency and C is the capacitance of the capacitor.

4. What factors affect the magnitude of inductive and capacitive reactance?

The magnitude of inductive reactance depends on the frequency of the AC current and the inductance of the inductor. The magnitude of capacitive reactance depends on the frequency and the capacitance of the capacitor.

5. How can inductive and capacitive reactance be reduced in a circuit?

Inductive reactance can be reduced by increasing the frequency or decreasing the inductance, while capacitive reactance can be reduced by decreasing the frequency or increasing the capacitance. Additionally, the use of resistors in the circuit can also help to reduce reactance.

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