Question

The circuit diagram shows a $4\Omega$ resistor and an $8\Omega$ resistor connected to a $6\,V$ battery. What is the potential difference (p.d.) across the $4\Omega$ resistor ?
A. $0.5\,V$
B. $2\,V$
C. $4\,V$
D. $6\,V$

Answer 1

This question utilizes the concept of resistors and electric circuits. First we will determine if the resistors are connected in series or in parallel combination. Then, we will find the potential difference across the resistors.

Complete step by step answer:
We can see that the resistors are connected parallel to each other.We know that in a parallel combination of resistors, the voltage remains the same throughout the circuit. Each resistor in parallel has the same full voltage of the source that is supplying power to it.

The resistors divide the total current amongst them. When $n$ number of resistors are connected in parallel, more current flows from the source than would flow for any of them individually. Thus, the total resistance is lower. Therefore, the potential difference across the $4\Omega$ resistor will be $6V$.

Hence, option D is the correct answer.

Note: All our house wiring is done in parallel. This is because, in parallel circuits, we can easily add switches to control each and every appliance individually. Also, in series circuits, each appliance does not get a constant voltage. This might result in the appliance malfunctioning and refusing to work.