Ammeter is always connected in series because it has low resistance.
Voltmeter is always connected in parallel. because it has high resistance.
So conditions is what happens when voltmeter and ammeter interchange their position..
Now ,as per conditions,
Ammeter is connected in parallel. So it has very low resistance…current is follow only low resistive path….so they act like short circuit.also chances of ammter get damaged.
Now,if Voltmeter is connected in series..then due to high resistance no current will flow through circuit..so novoltage drop occur. Voltage in same line is zero..its indicates zero.
A voltmeter is used to measure the potential difference across two point in a circuit. Since, in parallel connection the voltage in the branches remains same, and also the resistance of the voltmeter is very high due to which a very small current flow through the voltmeter. So, a voltmeter is connected in parallel to measure the voltage.
An ammeter is used to measure the current flowing through a component/circuit. Since, current remains same in series connection and also the resistance of an ammeter is very small due to which it doesn’t affect the current to be measured. So, an ammeter is connected in series to measure current.
Now if we change their positions suppose if an ammeter is connected in parallel then due to its low resistance the current will now flow through it possibly damaging the instrument.
and if a voltmeter is connected in series then due to its very high resistance no current will be allowed to flow and heat will start to build up, possibly causing a fire.