2 Explain in detail how you could measure the internal resistance of a
11 TwoTerminal B = source((0,0), DC, 0, "", "$V$");
12 TwoTerminal r = resistor(B.end, normal, 0, "", "$r$");
13 TwoTerminal R = resistor((0,u), normal, 0, "$R$", "");
14 TwoTerminal I = current((r.end.x, R.end.y), 180, "", "$I$");
15 wire(B.beg, R.beg, udsq);
16 wire(r.end, I.beg, udsq);
17 wire(I.end, R.end, nsq);
20 Make a circuit using a known resistance $R$ to connect the two
21 terminals of the battery, and measure the current $I$.
23 From Kirchoff's loop rule
27 r &= \ans{\frac{V}{I} - R}