A0.12-mu or micro ff capacitor, initially uncharged, is connected in series with a 10-kohm resistor and a 12-v battery of negligible internal resistance. approximately how long does it take the capacitor to reach 90% of its final charge?

The time is 2.8 ms.

Explanation:

Given that,

Capacitor = 0.12 μF

Resistance = 10 kohm

Voltage = 12 V

Charge Q = 0.9 Q₀

We need to calculate the time constant

Using formula of time constant

Put the value into the formula

We need to calculate the time

Using formula of time

Put the value into the formula

Hence, The time is 2.8 ms.