A network of three resistors of resistances 
, 
and 
is shown.
The individual currents in the resistors are 
, 
and 
. The total current in the combination of resistors is 
and the potential difference across the combination is 
. Show that the combined resistance 
of the network is given by:
A battery of electromotive force (e.m.f.) 
and internal resistance 
is connected to three resistors X, Y, and Z, as shown.
Resistor Y has a resistance of 
. The current in resistor X is 
and the current in resistor Y is 
. Calculate:
the current in the battery
the internal resistance of the battery
.
.
