Elec Class

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Solved exercise · level 4 of 5

Efficiency of a real generator

Skills: Measure, Calculate

Statement

Source G has an EMF E = 12 V and an internal resistance. V1 measures its terminal voltage under load, A1 the current.

Useful power = U × I, total power produced = E × I: compute the generator efficiency.

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

3 hints from Bastaya available in the lab
Solution

η = U / E = 9.89 V / 12 V = 0.825. The losses r·I² = 1 × 2.1052² W are dissipated in the source.

Course sheet of the chapter : Power, energy, efficiency

This chapter is covered by the paths: General electricity, ISL-oriented exercises

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
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R
rotate
C
chip brush
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drag background
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