Eh-2 Hysteresis
Published: Tuesday 14 March 2006 - Updated: Tuesday 29 March 2011
Aim
To demonstrate the B-H hysteresis curve.
Apparatus
- Hysteresis board
- Cathode ray oscilloscope
- Variac
Diagrams
Click on pictures to enlarge.
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Hysteresis Diagram 2 |
Hysteresis Diagram 1 |
Description
As the variac voltage is increased the full B-H hysteresis curve to saturation is displayed on the C.R.O.
The voltage across the resistor R1 is proportional to the current in the primary and corresponds to the magnetic field strength H. The induced emf in the secondary is V=kdB/dt by Faraday's Law. The RC circuit (an integrator) yields a voltage proportional to B.