yay thanks guys!!
Ok so voltage is the same in two components in parallel. but then if a voltmeter has a super high resistance that means the voltage it uses is close to zero. so there is no voltage drop across the voltmeter, which somehow enables it to measure the VOLTAGE drop of the resistor it is connected parallel to?
I think what's really bugging me is HOW the voltmeter is able to get the reading off the resistor. Not so much why it's connected in parallel because yeh voltage drop but like how does it get this reading if the voltage passing through the voltmeter is zero......?
THANKKKS AGAIN
Not sure where you got this idea from.
The voltage across a resistor is the same (unless there is an open circuit where the voltage floats).
So if you have high resistance there will still be a voltage drop across it of magnitude V = IR.
So the resistance here is constant. The voltage is what you are measuring and the current is dependent on the voltage.
The voltmeter will have some sort of dependent elements such as transistors or amplifiers which have an internal resistance in them.
The voltmeter is scaled and calibrated using some more complex combinational circuits. These combinational circuits determine the patterns shown on the 7 segment displays.
The voltage drop across the elements affects the output voltage in some components and then these are recalculated using the predetermined values of the voltage drops. How does it calculate you ask? Well this is what amplifiers are capable of. They can do complex calculations even involving calculus. In fact they are the reason why calculators work.
That's the "basics" of how modern digital voltmeters work. This is probably very confusing for you because you have probably heard of transistors and amplifiers and combinational circuits but you probably don't know what they are. If you are keen then research into them. But generally a digital voltmeter is very complex, however this is what makes them accurate.
Honestly don't worry about the digital voltmeter too much. Below you will definitely need to learn next year:
There is also another type of voltmeter which does not use internal resistance (this is a simple analog one).
There is the galvanometer, which you will learn about next year in HSC, which uses magnetism rather than internal resistances and complex calculations.
If you are lucky enough your school might have some that you can play around with. We had one and it was awesome to put the theory into practice.
