Topics
Transformer, Educational aids
William Layton proposes a demonstration1 designed to clarify the operation of a transformer. He considers the isolation transformer that has the same number of turns in the primary as in the secondary coils. This means that L1 = L2 = L and Φ1 = Φ2 = Φ, where L is the inductance of the coils, indexes 1 and 2 correspond to the primary and secondary coils, and Φ is a magnetic linkage through the coils. Layton asks a question about a transformer with initially closed switches A and B, as presented in Fig. 1:
Fig. 1.
View largeDownload slide

Transformer circuit.1 

Fig. 1.
View largeDownload slide

Transformer circuit.1 

Close modal

“What will happen to the bulb in the primary circuit if switch B is now opened?”

To answer this question, Layton considers the case when the secondary coil has...
AAPT members receive access to The Physics Teacher and the American Journal of Physics as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.