The voltmetre is used for measuring the electrical potential
difference between two points of a line,where as the
potential difference measured between two points of same
wire/line is zero.In short!the internal resistance of
voltmetre is generally high,so you cannot connect it in series.
The ammetre having minimum internal resistance,supports the
idea of connecting it in series,because you want to measure
the current of a wire and current is same in a circuit
connected in series.The net effect is that the setup of
equipment discussed above does not affect the circuit behaviour
if u connect the voltmeter in series, there is no power to
the later stages (like the source having high internal
if u connect the ammeter in parallel,there is a dead
short circuit of the source(if fuses used,blown-off &
chance of ammeter coil damage).
voltmeter used measure potential difference between two points and it has consist of high resistance and voltage will be drop at across the circuit so voltmeter will be connected parell to the circuit ammeter is low resistance,current will be drop at seresis to the circuit so ammeter will be connected seresis to the circuit