Question

In a simple circuit, the potential energy always used up as the charge reach the negative terminal? regardless of how much the resistance in the circuit?

Answer 1

If the 2 different circuit with only cell and wires(1 is copper wire another is iron) the energy changed to heat energy is same in both of these circuit so the charge would reach the negative terminal of the cell with zero potential energy?

Answer 2

Kirchoff's voltage law states that the sum of the potential differences around a closed circuit (loop) must equal 0. In other words, if you have a circuit with 2 resistors in series with a battery the equation would look like:
\[E_{batt} - I(R_{1}+R_{2}) = 0\]
If you had as circuit with two resistors in parallel with a battery, the equation would be:
\[E_{batt} - I(\frac{R_{1}R_{2}}{R_{1}+R_{2}}) = 0\]
I don't really understand your second question but note that it doesn't matter what the resistors are made of. What matters is how much resistance they provide. Since E=IR and E is assumed to be relatively constant, if the resistance goes down the current must go up (which will generate more heat)...and vice versa.

I hope this helps.

Answer 3

If i have a battery and a wire, if i connect the both end of the wire to both of the battery's terminal, will the current flow heat up the wire due to the resistance of the wire?

Answer 4

The resistance of a short piece of wire will be very low so the current will be very high...as high as the battery can provide (based on the internal resistance of the battery). So yes, it will heat up the wire.