(6)
\Step 1:
\A resistance of
is connected in parallel with resistance of
.
Find the equivalent resistance.
\Consider
is the equivalent resistance.
is connected in parallel to
.

The equivalent resistance is
.
Step 2:
\The equivalent resistance is connected in series with a resistance of
.
Now find the total resistance.
\Consider
is the total resistance.
So
is connected in series with
.

The total resistance is
.
Step 3:
\The above circuit is connected across a battery having an EMF of 18 V and an internal resistance of
.
Now find the total equivalent resistance.
\Consider
is the total equivalent resistance.
So
is connected in series with
.

The total equivalent resistance is
.
Find the total current in the circuit.
\Consider
is the total current in the circuit.
From ohms law :
.
Then total current is 
Substitute
in the total current.

The total current in the circuit is
.
Step 4:
\(6.1)
\Find the terminal voltage of the battery.
\Suppose that the battery with EMF
and internal resistance
supplies a current
through an external load resistor
, then the terminal voltage across the battery is
.
Substitute
in the terminal voltage.

The terminal voltage of the battery is
.
Step 5:
\(6.2)
\Find the current through each resistance.
\The current through
resistance is
.
The voltage across
resistance is

Voltage across
resistance is
.
Now find the voltage across the resistance
.
The terminal voltage is
.
The voltage across the resistance
is
.
The voltage is same in the parallel loop.
\So voltage across the
and
is
.
Find the current
.

Find the current
.

Solution :
\(6.1) The terminal voltage of the battery is
.
(6.2)
\The current through
resistance is
.
The current through
resistance is
.
The current through
resistance is
.