Refer to the following diagram to calculate the effective resista

SOLUTION

CONCEPT: 

Resistance:

• The measurement of the opposition of the flow of electric current through a conductor is called resistance of that conductor. It is denoted by R.

There are mainly two ways of the combination of resistances:

1. Resistances in series:

• When two or more resistances are connected one after another such that the same current flows through them are called as resistances in series.
• The net resistance/equivalent resistance (R) of resistances in series is given by:
• Equivalent resistance, R = R1 + R2

2. Resistances in parallel:

• When the terminals of two or more resistances are connected at the same two points and the potential difference across them is equal is called resistances in parallel.
• The net resistance/equivalent resistance(R) of resistances in parallel is given by:
• \(\frac{1}{R} = \frac{1}{{{R_1}}} + \frac{1}{{{R_2}}}\)

CALCULATION:

• Here 10 Ω, 20 Ω and 60 Ω are in parallel combination, therefore the resultant resistance is

\(⇒ \frac{1}{R_{para}} = \frac{1}{{{10}}} + \frac{1}{{{20}}}+\frac{1}{{{60}}}=\frac{10}{60}=\frac{1}{6}\)

⇒ R_para = 6 Ω 

Now 6 Ω and 12 Ω are in series, therefore the net resultant resistance is 

⇒ Rnet = 6 Ω + 12 Ω = 18 Ω