In a normal
series circuit like the one shown in figure 1a above, there exist a current
flow and the voltage drops across each of the resistors are directly
proportional to their resistances. If for any reason, the circuit becomes
‘open’ at any point as in the case of figure 1b, the following effects are
produced;
series circuit like the one shown in figure 1a above, there exist a current
flow and the voltage drops across each of the resistors are directly
proportional to their resistances. If for any reason, the circuit becomes
‘open’ at any point as in the case of figure 1b, the following effects are
produced;
i.
Since ‘open’ offers infinite resistance, circuit
current becomes zero. Consequently, there is no voltage drop across R1
and R2.
ii.
The whole of the applied voltage (i.e. 50V in
this case) is felt across the ‘open’ which is across terminal A and B in figure
1b.
The reason for
this is that R1 and R2 becomes negligible as compared to
the infinite resistance of the ‘open’ which has practically whole of the
applied voltage drop across it (as per voltage Divider Rule). Hence a voltmeter
connected across the terminal will read nearly 50V i.e. the supply voltage.
this is that R1 and R2 becomes negligible as compared to
the infinite resistance of the ‘open’ which has practically whole of the
applied voltage drop across it (as per voltage Divider Rule). Hence a voltmeter
connected across the terminal will read nearly 50V i.e. the supply voltage.
