[填空题]
In Fig. Below a (same as Fig. Below 5e20wkn-rc o s 4n9xemb), t6q1/ g*eb 6+ teycjzcphe total resistance is $15.0k\Omega$, and the battery’s emf is 24.0 V. If the time constant is measured to be $35.0\mu s$, calculate
(a) the total capacitance of the circuit $ \times10^{-9 }\;F$
(b) the time it takes for the voltage across the resistor to reach 16.0 V after the switch is closed. $ \times10^{-5 }\;s$
a
b