When you heat a certain substance with a difference of temperature

the heat (energy) you must give to it is

where

is the specific heat of that substance (given in J/(g*Celsius))
In this case

Observation: the specific heat of a substance is given in J/(g*Celsius) or J/(g*Kelvin) because on the temperature scale a
difference of 1 degree Celsius = 1 degree Kelvin
Answer: the difference in the number of turns in each coil
Explanation:
A transformer is a device which is used transfer electrical energy from one circuit to another. It uses coils - primary and secondary having different turns. The current passes through the primary coil which induces emf in the secondary coil. The increase in potential depends on the number of turns in the coil.

where V is the voltage and N is the number of turns.
Answer:
open source Software
Explanation:
An open source software can be any software made available within an open source license which means that anyone can access its source code, see that it was created and, as the question says, "study, change and improve it."
This is contrary to copyrighted or closed source software where you would require a license to use the software, however, we can not see or amend in the "building blocks" (i.e. code)