Capacitive reactance of the capacitor depends upona)Capacitance of condenserb)Frequencyc)Both a and bd)Neither a nor bCorrect answer is option 'C'. Can you explain this answer?

Question

Answer

The formula for capacitive reactance (Xc) is Xc=1/(wC) so it clearly depends upon both frequency and capacitance.

Answer

Capacitive reactance (symbol XC) is a measure of a capacitor’s opposition to AC (alternating current). Like resistance it is measured in ohms, but reactance is more complex than resistance because its value depends on the frequency (f) of the signal passing through the capacitor. Reactance is also inversely proportional to the value of capacitance (C), i.e. the value of XC at any frequency will be less in larger capacitors than in smaller ones. All capacitors have infinitely high values of reactance at 0Hz, but in large capacitors, the reactance falls to a low level at much lower frequencies than in smaller capacitors. Hence, larger capacitors are preferred in low frequency applications.

Answer

Xc=1÷wc=1÷2pi×frequency xc

Answer

Capacitive reactance is a property of a capacitor that determines its opposition to the flow of alternating current (AC). It is denoted by the symbol Xc and is measured in ohms (Ω). The capacitive reactance of a capacitor depends on two factors: the capacitance of the capacitor and the frequency of the AC signal.

Capacitance of the capacitor:
- The capacitance of a capacitor is a measure of its ability to store electrical energy. It is determined by the physical characteristics of the capacitor, such as the size of its plates, the distance between them, and the dielectric material between them.
- The larger the capacitance of the capacitor, the more charge it can store for a given voltage. As the capacitance increases, the capacitive reactance decreases.
- This is because a larger capacitance allows more charge to be stored, which means a higher current can flow through the capacitor. Therefore, the opposition to the flow of current decreases, resulting in a lower capacitive reactance.

Frequency of the AC signal:
- The frequency of the AC signal refers to the rate at which the direction of the current changes. It is measured in hertz (Hz) and represents the number of cycles per second.
- As the frequency of the AC signal increases, the capacitive reactance decreases.
- This is because at higher frequencies, the time available for the charge to accumulate on the plates of the capacitor decreases. As a result, the opposition to the flow of current decreases, leading to a lower capacitive reactance.

Both factors:
- The capacitive reactance of a capacitor is determined by both the capacitance of the capacitor and the frequency of the AC signal. Both factors have an inverse relationship with the capacitive reactance.
- The larger the capacitance and the lower the frequency, the lower the capacitive reactance.
- On the other hand, the smaller the capacitance and the higher the frequency, the higher the capacitive reactance.

In conclusion, the capacitive reactance of a capacitor depends on the capacitance of the capacitor and the frequency of the AC signal. Both factors affect the opposition to the flow of current through the capacitor.

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