1. Oct 6, 2013

### shenjie

Hi all, can i know is it true that charge flow is equal to zero at steady state current? Or is the rate of charge flow equal to zero. Thanks :)

2. Oct 6, 2013

### Crazymechanic

Not sure what you mean exactly but in a current carrying conductor the charge is the electron ,
current itself is the movement of electric charge so how come the movement of charge add up to zero?

3. Oct 6, 2013

### PhysEng

steady state current means that a constant charge per unit time is flowing through the wire, device, etc.
zero current is but one case of steady state current.

4. Oct 6, 2013

### ZapperZ

Staff Emeritus
Steady state here means that dI/dt, or the rate of change of current, is zero, meaning that I (current) is a constant.

Zz.

5. Oct 6, 2013

### shenjie

Then does it have any relationship to the charge flow?? it is actually an ode question. i have obtain a q(t) equation in the first part, q = charge. The question ask to obtain steady state current from q(t)

6. Oct 6, 2013

### PhysEng

Another interpretation could be that the current is periodic and its frequency and amplitude are unchanging.
When a sinusoidal current is applied to a circuit, a transient voltage and current is produced. This is followed by a "steady state" voltage and current. But neither voltage nor current is constant (including zero). They are steady in the sense that they behave in steady periodic form with steady amplitude and period.

7. Oct 6, 2013

### ZapperZ

Staff Emeritus
You appear to not understand the relationship between charge flow, and current.

I = dq/dt. If I is a constant (as in the steady state current), what does it say about dq/dt?. And if dq/dt is a constant, what is q(t)?

If this is related to school work, then (i) it should have been done in the HW/Coursework forum, and (ii) we've almost given you too much information.

Zz.