What is the total resistance in the following circuit element?

The correct answer is option "4"

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:

Calculation:

In the given figure of resistance two identical resistances "R" are in parallel and then in series with otherr identical resistance "R"

The parallel combination of R and R would be

R' = R×R/(R + R)

R' = R/2

The R' is in a series with R.

So R equivalent would be

R_eq = R/2 + R

= 3R/2