What is the expression for the voltage across a capacitor as it is discharging in a simple RC circuit? (Use the following as necessary: V0 for the initial voltage, R for the resistor, C for the capacitance, and t for the time.)
What is the ratio of V/V0 at time t = τ?
What is the ratio of V/V0 at time t = τ?
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1. voltage on a cap, charging
v = v₀[1–e^(–t/τ)]
v₀ is the final voltage
2. voltage on a cap, discharging
v = v₀e^(–t/τ)
v₀ is the initial voltage on the cap
R is resistance in ohms,
C is capacitance in farads
t is time in seconds
RC = τ = time constant
v = v₀e^(–t/τ)
v/v₀ = e^(–τ/τ) = 1/e = 0.368
v = v₀[1–e^(–t/τ)]
v₀ is the final voltage
2. voltage on a cap, discharging
v = v₀e^(–t/τ)
v₀ is the initial voltage on the cap
R is resistance in ohms,
C is capacitance in farads
t is time in seconds
RC = τ = time constant
v = v₀e^(–t/τ)
v/v₀ = e^(–τ/τ) = 1/e = 0.368