Is the energy loss in a voltage drop equal to heat/mechanical work/light emitted?
I am wondering if the energy loss in a voltage drop over an entire circuit is equal to the energy transferred from the circuit (e.g. light/sound/mechanical energy/heat).


Yes. Energy is conserved. Any electrical energy that is lost by the circuit is transformed into some other kind of energy.

It is often heat, for example in a resistor or a diode.

It could be something like chemical energy, in a battery charger.


  If this is true, wouldn't that make it so that the voltage drop in a short circuit would be 100% since all of the electrical energy must be converted into something else?


Yes, the energy lost from the circuit will be converted to heat. The wire forming the short circuit will heat up (because of its resistance, even though that resistance is too small to matter in more useful circuits), as will the battery (because of its internal resistance).