Electronics - Voltage and Current - Discussion

Voltage (Electrical potential) is an electrical force applied to move a charge from one point (A) to another point (B). ie) Work done (Joules).

At point A high is available and in moving the charge to point B as work is done some potential is consumed. Hence potential at B will be less than at A. Hence a potential difference between points A &B.

A voltmeter is used to measure the potential difference between two points. Any measurement of difference is wrt to a reference point. Hence, a voltmeter is connected across (Parallel) two points.

If voltmeter is connected in series itself it is drop voltage and it does not measure the voltage in branch elements. Voltmeter put across parallel with any branch it is measure the voltage across that branch.

And ammeter is connected across parallel with any branch it does not measure the current. Ammeter is connected in series with any branch is measure the current through that branch.

*voltmeter is used to measure voltage.

*if you want to measure V then yo ve to connect it in parallel since V remains same in parallel paths.

*so in order to avoid flow of current through voltmeter (coz it may lead to reduction of V) it is designed in such a way so that it gives very high impedance (ideally infinity).

Votmeter is used to measure Voltage.

Why it is used in parallel because to make reference with ground.

To understand in simple how your mummy measures your potential?

By Comapring you with your neighbour friend taking them as reference :)

Voltmeter should placed in parallel with a circuit element because the internal resistance of voltmeter is very high. If it is connected in series it prevents the flow of current since it increases the total resistance of the circuit.

@Somveer,

Nice question : I think we should increase the resistance of ammeter. Here galvano and ammeter use for measure current, but galvano can do one more good thing, this is, it can also show the direction of the current AC.

Actually voltage is otherwise potential difference. So it can be measure only between two point. So voltmeter is always used in parallel with circuit whereas ammeter is used to measure current in series of any circuit.

Actually voltage is also be called as potential difference. This P.D. , is determine in between the two terminals of a component only. Because voltage drop has same quantity in the parallel connection.

By the definition of voltage we know that it is the potential difference between two points so we connect voltmeter parallel.

i.e., we connect one probe at one point and second probe at other point.

Voltmeter range can be extended by connecting a high resistance in series so that that will acts as multiplier.

Ammeter range can be extended by connecting more and more shunt resistances.