Question

Lab 12 Individual Wrap Up

Wrap up question 1: While an ideal battery has no internal resistance, real batteries do. What effect would it have on a circuit (in terms of battery voltage and current in the circuit) if a battery has a large internal resistance? Explain.

Wrap up question 2: Using the potential vs distance around the circuit plot, draw or describe the single loop circuit that it matches (starting in the lower left corner and going clockwise). Label all potential and resistance values, if the current is 2 A.

lab11WUfigure.jpeg

Wrap up question 3: Given the results of the last experiment in Part 6, would two resistors in parallel have a combined resistance that's bigger or smaller than each resistor alone? Justify using your experiment results.

Answer 1

Answer 1:

For real batteries

V=E-IR

where V is voltage in circuit & E- Electromotive force (EMF)

if internal resistance is 0 then

V=E

so we will get more output ( in case of discharging) because there is no power lost in internal resistance. Means more efficiency.

If there is large internal resistance, effective voltage in the circuit will decrease.

Answer 2: According to the graph, there is constant voltage of 2 V and then drops to zero, means there is resistance across which voltage is 2 V and current as mentioned is 2A ,hence resistance is 1ohm.

Then voltage increases from 0 to 6V which means there is battery of 6V .

Then it decreases from 6V to 2 V which means there is resistance across which voltage is 4V and current is 2A so resistance is 2 ohm.

Answer 3: Since the part 6 is not mentioned in question, it can not be answered specifically .

but in case of parallel resistance, let total resistance is R and individual resistances are R1 and R2. Then,

So, the total resistance is always smaller than individual resistance.