Alas, it is a bit of a swindle. The galvanometer scale
supposedly represents current, and might even be labeled
and calibrated as such. However, that's not what's actually
being measured here. There is virtually no chance that a
galvanometer of the suggested kind has a low enough input
impedance to function as an ideal current meter. Instead,
it is functioning as an ill-calibrated voltmeter.
This is ironic, since the physics is better understood in
terms of voltage anyway. We're talking about Faraday's law,
which is incorporated into the Maxwell equations. The form
and meaning of this law are reeeeeally well known.
*Voltage = flux dot*
The distinction between voltage and current is nontrivial
in the 5k10.15 situation. Specifically:
* Using an ideal ammeter, if you make two loops in parallel
and move both of them relative to the magnet, you would
expect to get the sum of the currents. This is not observed
using the usual 5k10.15 setup.
* In contrast, using an ideal voltmeter, if you make two
loops in series and move both of them relative to the
magnet, you get the sum of the voltages. This is precisely
what is observed.
In all situations whatsoever: Faraday's law (i.e. voltage
equals flux dot) works for all loops, even including extreme
cases such as non-conducting loops, imaginary loops, and
superconducting loops ... whereas the notion of induced
current fails in many cases.
I think concepts are important. The correct concept here
is induced voltage ... not induced current.
Suggestions:
++ Always express Faraday's law as an induced voltage
(not current). *Voltage = flux dot*
++ Measure it using a voltmeter (not galvanometer).
More specifically: In 5k10.15 you can use the same hardware;
just improve the labeling. For example, the d'Arsonval meter
could be labeled 50 μA full-scale *and* 50 mV full scale.
Refer to it as a voltmeter when appropriate.