I have been learning about voltage and I am still a bit confused.
A battery having 1.5 volt means that it has electrical potential energy difference of 1.5 volt right?
That means this potential to do work or energy is supplied when the battery is connected to the circuit and electrons flow as they recieve the energy?
1.5 V is a measure of electrical potential. It is not energy, so electrical potential energy doesn't make sense.
One way to look at EMF is the potential of charge to do work. 3 Coulombs at a potential of 5 V can do 15 joules of work when flowing down to 0 potential. This is like a brick can do work while falling from a high spot (high gravitational potential) to a low spot (lower gravitational potential).
A battery is a pump for charge. As some charge flows from the higher to lower potential, the battery keeps replacing that charge at the high potential. This is like a pump moving water uphill so that you can run a water wheel from it. The water wheel is your circuit that is using power from the water to perform its function. The battery is the pump that takes the water from the bottom of the water wheel (at low potential) and moves it back up to the top (at high potential), where it can be used to run the water wheel again.
A battery having 1.5 volt means that it has electrical potential energy difference of 1.5 volt right?
There is a potential difference of 1.5 V.
This means that if you moved a +1 C test charge from one terminal to the other, you would need to do 1.5 J of work on the charge to move it from the negative terminal to the positive terminal. And this would add 1.5 J to the electrical potential energy of the test charge.
But the potential difference is defined even if there is no charge there to be moved or to have potential energy. Just like the electric field is there ready to apply a force to any charge that comes along, even when there's no charge actually there to have a force applied to it.
That means this potential to do work or energy is supplied when the battery is connected to the circuit and electrons flow as they recieve the energy?
When you connect the circuit, then the battery actually does work on charges to push them through the circuit. The "potential" or possibility to do work is there even before the circuit is connected.
