Electrical Engineering - Capacitors - Discussion
Discussion Forum : Capacitors - General Questions (Q.No. 22)
22.
An uncharged capacitor and a 1 k
resistor are connected in series with a switch and a 6 V battery. At the instant the switch is closed, the voltage across the capacitor is

Discussion:
12 comments Page 1 of 2.
Pakkurthi Naresh Kumar said:
5 years ago
Initially, as given in the problem the capacitor is in uncharged condition.at the instant when the switch is closed the voltage across the capacitor is zero because the capacitor only charges when an infinite amount of current flows through it. So, at the time of starting not much amount of current flows through ckt and hence, the voltage across the capacitor is 0
We know;
C = Q/V.
V = Q/C.
And also Q=idt at the starting there is no change in current with respect to time due to that there is no change accumulation.
We know;
C = Q/V.
V = Q/C.
And also Q=idt at the starting there is no change in current with respect to time due to that there is no change accumulation.
Mani said:
1 decade ago
Voltage across the capacitor cannot change immediately since, it requires infinite current to flow. This is physically impossible. (i=C dv/dt). Since, before closing the switch voltage across the capacitor is ZERO and at the instant switch has been closed also voltage across the capacitor is ZERO.
Stuti kushwaha said:
10 years ago
C does not allow the sudden change in voltage so here at t = (0-) C have no charge it is given in question then at t = (0+) C behave like a short circuit and we know that short circuit have 0 voltage.
Usman said:
3 years ago
The capacitor does not allow sudden changes in voltage, therefore, the voltage across the capacitor is zero. Similarly, Inductor does not allow sudden changes in current.
(2)
RAHIM SHEIKH said:
10 years ago
Actually voltage across capacitor can not change instantaneously so in this change case answer is zero.
Shadan said:
7 years ago
Q=CV,
V=Q/C,
Because capacitor is uncherged soQ=0 c.
So V=Q/C= 0/C =0V.
V=Q/C,
Because capacitor is uncherged soQ=0 c.
So V=Q/C= 0/C =0V.
Hassan said:
6 years ago
Here it's using DC source (battery) so the circuit will act like open.
(1)
Shubham said:
9 years ago
The capacitor rating is independent of voltage hence it's zero.
Rathi said:
1 decade ago
Yes, the capacitor takes some time to charge.
Waseem khan said:
6 years ago
For DC source, capacitor act like open.
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