Electronics - Capacitors - Discussion

Discussion Forum : Capacitors - True or False (Q.No. 11)
11.

In the given circuit, the voltage across the capacitor 1 ms after the switch is closed is 11.61 V.

True
False
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
5 comments Page 1 of 1.

Nagashree said:   1 decade ago
T=RC
So wil get T=0.672ms
1ms=15v
for 0.672ms wil get 10.08v

Ranjith Garuda said:   1 decade ago
When the switch is closed the capacitor starts discharging through resistor. The discharge equation is. Vc=Vs*e^ (-t/rc). Substituting for Vc=15v, t=1ms, r=1. 2k & c=0. 56uf. We arrive at Vo=3. 387V.

Here 1ms specified is the elapsed time after the switch is closed, and not the time constant to check with.

Shambu said:   5 years ago
Thanks for the explanations.

Pritam said:   5 years ago
TRUE.

After closing switch, the capacitor starts discharging.
Vc=Vs*e^(-t/T).
Vc=15*e^(-10^-3/(.56*10^-6*1.2*10^3))=3.387V.
15-3.387=11.61V.

Pritamnutil said:   4 years ago
@All.

You don't need to subtract 3.387 to 15. 3.387 is the value of voltage in the capacitor after 1ms. Just follow the equation Vc = E(e^-(t/T)) for a discharging capacitor.

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