For RC values R = 1 kΩ and C = 1 μF, what is the time constant τ in seconds?

For RC values R = 1 kΩ and C = 1 μF, what is the time constant τ in seconds?

• A. 0.01 s
• B. 1 s
• C. 1e-6 s
• D. 0.001 s

Answer: (D)

The time constant of an RC circuit is the product of resistance and capacitance. Convert the values to base units: R = 1 kΩ = 1000 Ω, C = 1 μF = 1×10^-6 F. Multiply: 1000 × 1×10^-6 = 1×10^-3 seconds, which is 0.001 s (1 millisecond). This τ sets how quickly the circuit responds to changes; after one time constant, the capacitor voltage moves toward its final value, and in this case the time constant is 0.001 s.

The time constant of an RC circuit is the product of resistance and capacitance. Convert the values to base units: R = 1 kΩ = 1000 Ω, C = 1 μF = 1×10^-6 F. Multiply: 1000 × 1×10^-6 = 1×10^-3 seconds, which is 0.001 s (1 millisecond). This τ sets how quickly the circuit responds to changes; after one time constant, the capacitor voltage moves toward its final value, and in this case the time constant is 0.001 s.