Elec Class

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Solved exercise · level 4 of 5

Plotting U = f(I)

Skills: Measure, Analyse

Statement

Source G has an unknown EMF and internal resistance. V1 measures its voltage, A1 the current, and rheostat P1 varies the load.

Move the wiper of P1, record at least 4 (U, I) pairs with the "Record" button, then read the EMF E (voltage at zero current) on the graph.

Parametric exercise: the values change with every draw; these are one example.

2 hints from Bastaya available in the lab
Solution

The points line up on U = E − r·I; the intercept gives E = 12 V, the slope −r = −3 Ω.

Course sheet of the chapter : Real generators & loads

This chapter is covered by the paths: General electricity, Measurement prep

Other exercises of the chapter

Simulated time00:00:00
Q = I·t-
W = P·t-

Circuit diagram CEI 60617

How does it work?

Each big hole is a circuit node: you push one leg of a component into it. The 4 small holes around it are connected to it: chips and leads plug in there.

  1. Place a component Drag it from the palette: it snaps onto the grid. R rotates it.
  2. Bridge neighbouring holes Pick the jumper chip (or C) and drag on the board: bridged holes become a single node.
  3. Draw a lead For long links and the power supply: from one big hole to another, or to a terminal.
  4. Close the loop The circuit is solved live (Ohm, Kirchhoff) and the diagram follows.

Shortcuts

Del
delete
R
rotate
C
chip brush
Esc
cancel
wheel
zoom
0
fit the board
drag background
pan

Confirmer

Renommer

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