Question

The equivalent resistance between points 1 and 2 of the circuit shown is:

A) 4 Ω
B) 4.5 Ω
C) 6 Ω
D) 3 Ω
E) 2.5 Ω

Answer 1

Concepts and reason

The concepts used to solve this problem are resistors in series, resistors in parallel, Ohm’s law, and current division rule.

Initially, use the concept of resistors in series and parallel connection to calculate the net resistance of the circuit.

Fundamentals

The series circuit is that all the resistors are arranged in a chain.

The net resistance is calculated by simply adding the values of each resistor.

The expression for the net resistance in a series circuit is as follows:

Here,, , , and are the resistances, and the net resistance is .

The parallel circuit is that all the resistors are arranged with their heads connected together.

The expression for the net resistance in a parallel circuit is as follows:

The circuit diagram is depicted below:

In the circuit resistors, , , and are connected in a series, and the resistor is connected in parallel with the net resistance.

The net resistance for , , and is given by the following expression:

Substitute for , for , and for .

The net resistance is connected in parallel with .

The net resistance for , is given by the following expression:

Substitute for and for .

The incorrect options are as follows:

The circuit diagram is depicted as follows:,

In the circuit resistors, , , and are connected in series, and the resistor is connected in parallel with the net resistance.

The net resistance for , , and is given by the following expression:

Substitute for , for , and for .

The net resistance is connected in parallel with .

The net resistance for , is given by the following expression:

Substitute for and for .

Therefore, the correct option is as follows:

Ans:

The net resistance between points 1 and 2 is .