Hey there Arnab Majumder! Look, when it comes to capacitance and DC current, it's a bit of a tricky business. See, the formula you Arnab Majumder mentioned, Xc = 1/(2πfC), indicates that capacitive reactance is inversely proportional to frequency. So, as the frequency approaches zero, the reactance becomes infinite.
Now, DC current is essentially a constant current with a frequency of zero. According to the formula, you'd expect infinite reactance, which might suggest that DC current can't pass through a capacitor.
But here's the twist – when we talk about the behavior of capacitors in DC circuits, we consider them as open circuits. In the steady state, a capacitor blocks the flow of DC current, creating an open circuit. However, during the transient phase (when the circuit is initially connected or disconnected), some current can flow to charge or discharge the capacitor.
So, while the formula implies infinite reactance at DC, in practical terms, a capacitor acts as an open circuit, preventing the continuous flow of DC current once it reaches a steady state. It's a bit counterintuitive, but that's how capacitors roll in DC circuits.
Arnab Majumder Capacitors are DC open circuits that prevent continuous current flow, store energy, and filter out AC components. They block DC current but can pass AC signals, making them useful for AC coupling and filtering. The formula Xc = 1/(2πfC) accurately predicts infinite reactance for DC, blocking sustained current flow. They are also used in timing circuits, power supply smoothing, and other electronic applications.
Hi, from a mathematical perspective, a DC step is a unit step function. You can find the frequency elements ω in a unit step function u(t) by applying the Fourier Transform F[u(t)] = (πδ(ω)+1/jω) where ω is the frequency.
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