The discussion focuses on calculating the potential difference in a potentiometer circuit, specifically addressing the relationship between electromotive forces (E1 and E2) and resistances (Rxy and Rxt). The key conclusion is that when the galvanometer reading is zero, the potential at point T equals E2, regardless of E1's value. The potential difference per unit length of the wire XY can be determined by dividing E2 by the length XT. This clarification resolves confusion regarding the connections and current flow in the circuit.
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E1-E2?gneill said:
No. E2 is not connected to point T.Janiceleong26 said:
I'm confused .. Why isn't E2 connected to T?gneill said:
Because there's the lengths XT and TY of resistive wire between E2 and T. There is some (unknown) current running through those lengths, causing potential differences.Janiceleong26 said:
Okay.. So the p.d. across XT is XT/XY x E1?gneill said:
No. Forget about E1 for now; you don't have a value for it. What you are to assume is that you know E2, and that the galvanometer reading is zero.Janiceleong26 said:
Potential at T is equal to E2gneill said:
Right! Note that it doesn't matter what E1 is. As soon as the galvanometer shows zero current, the potential at point T must match E2.Janiceleong26 said:
Yeah! It's E2 divide by the length XT. Thanks !gneill said: