PURPOSE: To demonstrate the effect of changing the number of turns in the secondary of a transformer.
DESCRIPTION: Use the variac to put 75VAC at 60 Hz onto the primary coil of the transformer. The secondary coil is created by looping a wire around the transformer core and connecting it to the AC voltmeter. The voltage produced is proportional to the number of turns in the secondary coil - 3 VAC RMS for 10 turns, which is approximately 10 volts peak-to-peak on the oscilloscope.
REFERENCES: (PIRA 5K30.10) See also Demonstration K3-04: DEMOUNTABLE TRANSFORMER - V VERSUS N - PROJECTION METER, which is this same experiment using a projection AC voltmeter to observe the secondary voltage.
EQUIPMENT: Demountable transformer core with 250-turn primary coil, long wire with banana plugs, and oscilloscope on scope/TV cart.
SETUP TIME: 5 min.
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