PURPOSE: To demonstrate the hysteresis loop for an iron transformer core.

DESCRIPTION: This demonstration shows the standard hysteresis curve with the magnetic induction B plotted on the vertical axis and the applied field H plotted on the horizontal axis. The value of H is obtained by using the voltage across a 1 ohm resistor in series with the primary coil of the transformer. The value of B in the core of the transformer is obtained as the voltage across a capacitor in series with a resistor and the secondary coil of the transformer. A variac adjusts the primary voltage so that the interesting parts of the hysteresis loop can be seen.



EQUIPMENT: Variac, pre-mounted hysteresis circuit, demountable transformer with 250 turn primary and 500 turn secondary coils, dual trace oscilloscope with scope/TV cart.

SETUP TIME: 5 min.

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