Engineering Discipline Practice Test

The RC time constant is the product RC. It characterizes how fast an RC circuit responds to a change, and after one time constant the capacitor voltage is about 63% of the way to its final value.

Compute with the given values: R = 1 kΩ = 1000 Ω, C = 2 μF = 2×10^-6 F. RC = 1000 × 2×10^-6 = 2×10^-3 s = 2 ms.

So, the time constant is 2 milliseconds. The other options would correspond to different RC products (for example, 2 μs would require RC = 2×10^-6 s, 2 s would require RC = 2, and 0.5 ms would be RC = 5×10^-4 s).