Question

In the circuit given below, the voltage across capacitor when switch is closed at t = ∞ is ____________

(a) 50 V

(b) 20 V

(c) 30 V

(d) 7.5 V

I have been asked this question in my homework.

This interesting question is from Calculation of I(0+), di/dt(0+), d2I/dt2(0+) in Circuits Involving both Capacitor and Inductor topic in division Application of the Laplace Transform in Circuit Analysis of Network Theory

Answer 1

The correct option is (a) 50 V

To elaborate: From the figure, we can infer that,

Voltage across capacitor = voltage across 10 Ω resistance.

Now, voltage across the 10 Ω resistance = \(\frac{100}{10+10}\) X 10

= \(\frac{100}{20}\).10

= 50 V.