On 28/03/2018 17:54, whisky-dave wrote:
On Wednesday, 28 March 2018 17:46:46 UTC+1, Sam wrote:

No, emf is volts not current.

you're funny. And you seldom learn.

https://en.wikipedia.org/wiki/Electromotive_force

Electromotive force, abbreviated emf (denoted E {\displaystyle {\mathcal {E}}} {\mathcal {E}} and measured in volts),[1] is the electrical intensity or "pressure" developed by a source of electrical energy such as a battery or generator.[2] A device that converts other forms of energy into electrical energy (a "transducer") provides an emf at its output

Explain what a current is, what controls the amount and how it is produced.

EMF is measured on volts as it says, what controls the amount is the restistance or impedence or reactance. Without a PD or EMF you don't get current.

You haven't defined what a current is - ie it a flow of electrons.

I always understood that the magnitude of the EMF/PD also controls the
electron flow and hence the current.

Basic formula:

I=E/R