Elec Class

learn electricity hands-on
0 1 / 20

Solved exercise · level 3 of 5

Operating temperature

Skills: Calculate

Statement

At what temperature is the field winding of a running generator, given that its resistance is 120 Ω at 25 °C and 153 Ω in operation? (α = 0.004 /°C)

Rθ₁ = 120 Ω · θ₁ = 25 °C · Rθ₂ = 152.7 Ω · α = 0.004 /°C

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

Guided problem in 4 steps: unknown, formula, units, data, result.

1 hint from Bastaya available in the lab
Solution

R₀ = 120 / (1 + 0.004 × 25); θ₂ = (Rθ₂ / R₀ − 1) / α = 100 °C.

Course sheet of the chapter : Ohm's law & resistance

This chapter is covered by the paths: 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
delete
R
rotate
C
chip brush
Esc
cancel
wheel
zoom
0
fit the board
drag background
pan

Confirmer

Renommer

Importer un montage

Export