Current versus voltage, Very Easy (but stuck)

AI Thread Summary
The discussion revolves around a homework problem involving a circuit with a capacitor and a voltage source, where the task is to graph the current over time based on a trapezoidal EMF versus time graph. The participant notes that Ohm's law (V = I/R) is not directly applicable due to the absence of a resistor, leading to the question of whether the current graph mirrors the voltage graph. It is suggested that while a resistor can be included for practical considerations, it won't alter the shape of the current graph. The conversation emphasizes the need to establish relationships between EMF, capacitance, and current through relevant equations to solve the problem effectively. Understanding these relationships is crucial for accurately depicting the current's time dependence in the circuit.
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Homework Statement


The problem gives a graph of Emf versus time, in a circuit consisting of capacitor C and voltage source e. It asks to draw the time dependence of the current I in the circuit.


Homework Equations


The graph looks like a trapezoid, positive slope starting at Emf=0 t=0, getting to t1 where the slope becomes 0, until t2, where it becomes a negative slope, and travels to t4 where it reaches Emf = 0


The Attempt at a Solution


I know for Ohms law it states V = I/R, but there isn't a Resistor in the circuit given. Would this just show that the current graph should look exactly the same as voltage graph?

Please help, thank you.
 
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You can put a resistor in (after all the leads always have some resistance), but this will not change what the drawing of the time dependence of the current looks like.

How about some equations to begin with? How are emf, capacitance and current related? You need two equations for starters.
 

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