Physics

Problem

A prototype alarm circuit uses a

4.7\,\mu\text{F}

capacitor that must reach

90\%

of its final charge in no more than

25\,\text{ms}

. Resistors are limited to the following E12 series values:

1.0\,\text{k}\Omega

2.2\,\text{k}\Omega

3.3\,\text{k}\Omega

, and

4.7\,\text{k}\Omega

. Which resistor is the largest value that still meets the timing requirement? a)

1.0\,\text{k}\Omega

4.7\,\text{k}\Omega

2.2\,\text{k}\Omega

3.3\,\text{k}\Omega