When Does a Capacitor Charge Linearly?

[anonymousphys]

Homework Statement

When a does a capacitor increase in charge linearly?

Homework Equations

C=Q/V

The Attempt at a Solution

If I am correct, it is when the capacitor is being directly charged by a battery. When there is a resistor, we get an RC circuit scenario where capacitor charges exponentially.

 

[Jmf]

Linearly with respect to what? time? Can V change too?

If an ideal resistor were charged with an ideal (no internal resistance) battery, the plot of charge against time would not be linear but would look like a step, from what I understand.

But of course in practice this is impossible, since there will always be some measure of resistance in the circuit. Does this help clear things up?

Here's an interesting question: If V were to change over time, how would the plot of V against time look if the plot of Q against time was linear? (I think maybe this was what you were meant to work out).