# How to evaluate, how much current flows in the circuit?

Please take into advisement, that I'm quite a beginner in subjects of physics and especially about electricity. Lately I've decided, that I want to learn more on basics of electronics and I've started reading about it, but a few things still are unclear for me.

I understand, that the voltage is the force, which pushes electrons through the wire. I also understand, that current is amount of electrons pushed by the wire in time. It's also clear for me, that power source, such as battery, has defined voltage, which it can provide. What is unclear:

1. How can I determine, how much current will flow through the circuit? Suppose, that I connect a 1.5V lightbulb to a 1.5V battery - how much current will flow through this circuit?

2. Too high voltage will fry the lightbulb (or other resistor), because voltage (being an actual electrical energy, as I understand that) will cause too much heat in the resistor. But is it possible to apply too much current to a resistor?

3. Battery capacity is expressed in mAh. Say, that the battery has 1200 mAh = 1.2 Ah = 72 Amin (ampminutes) = 4320 Asec (ampseconds). Is it actually (physically) possible to drain 4320 amps from this battery in a second? If not, what is the restriction, which prevents one from doing so? (not that I want to try :))

-