Question

A wire of resistance $100 \Omega$ is stretched to 1.1 times its initial length, volume remaining constant. The new resistance of the wire is
a) $110 \Omega$
b) $2.21 \Omega$
c) $1.21 \Omega$
d) $1.33 \Omega$

Answer 1

Hint: We know that a resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses. Most common, modern resistors are made out of either a carbon, metal, or metal-oxide film. In these resistors, a thin film of conductive though still resistive material is wrapped in a helix around and covered by an insulating material. Based on this concept we have to solve this question.

Complete step by step answer:
We know that Resistance is a measure of the opposition to current flow in an electrical circuit. Resistance is measured in ohms, symbolized by the Greek letter omega ($\Omega$). Conductors are known as materials that offer very little resistance where electrons can move easily.
It is also known that the electrical resistance of a circuit component or device is defined as the ratio of the voltage applied to the electric current which flows through it if the resistance is constant over a considerable range of voltage, then Ohm's law, $I=V/R$, can be used to predict the behaviour of the material.
We know that the length of the wire is directly proportional to the resistance of the wire. Hence, the net resistance would also increase 1.1 times or in the same proportion that is $110 \Omega$ if the wire is stretched 1.1 times its initial length, while the volume remains constant.

Therefore, the correct answer is Option a.

Note: We should know that when the current flows through the resistor, it will always generate a voltage drop, and which is mainly reflected in the decrease of the output current and the voltage. Resistors don't reduce current and voltage instead it opposes flow of current and produces drop in voltage across the terminals. Resistor values are carefully selected by the circuit designer to allow the circuit to work correctly. While there is some allowable tolerance, it won't usually be as much as a different value in the series. Resistors do not have polarity. Resistors are devices and materials that resist the flow of an electric current.
It should know that the resistance does not have polarity. The resistor opposes the flow of electrons. The flow of electrons is from lower potential to the higher potential. But the resistance offered by a resistor will be the same for flow of electrons in either direction.