not asking for lab analysis of data, just explanation of what to do with the mea
ID: 1661760 • Letter: N
Question
not asking for lab analysis of data, just explanation of what to do with the measured values to get Rs. I see V=R*I graph will get me R as slope, but what to do from there? How to express V in terms of I, Vs, and Rs.
A battery is a voltage source, or a device that produces a voltage difference Vs between its poles. Let us connect a load, resistor RL between these poles The smaller the resistor, the more current flows. As we lower this resistor, eventually the chemical reaction inside the battery cannot keep up with the demand and the voltage V across the battery drops, or VExplanation / Answer
From the circuit shown if we apply Kirchhoff's voltage law we get
Vs = IRs + IRL
And the voltmeter voltage being measured is
V = IRL
Therefore
Vs = IRs +V
V = Vs - IRs
From above equation when current I = 0
V = Vs i.e when no current flows through circuit then terminal potential difference V will be equal to emf of the battery.
When V = 0 ; Vs = IRs or
Rs = Vs / I
The slope of the V-I graph will be negative and the value of slope will give the internal resistance
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