Question

How will the resistance be affected if the various parameters are changed as follows?
$\begin{array}{cc}\text{i) Length increases}& \text{x) Resistance increases}\\ \text{ii) Area increases}& \text{y) Resistance decreases}\\ \text{iii) Resistivity decreases}& \text{z) Resistance remains the same}\\ \text{iv) Temperature increases}& \\ \text{v) Velocity increases}& \end{array}$

• A. (i-x) (ii-x) (iii-y) (iv-x ) (v-z)
• B. (i-x) (ii-y) (iii-y) (iv-z ) (v-z)
• C. (i-y) (ii-y) (iii-z) (iv-x ) (v-y)
• D. (i-x) (ii-y) (iii-y) (iv-x ) (v-z)

Answer 1

The correct option is D

(i-x) (ii-y) (iii-y) (iv-x ) (v-z)

The resistance of a conductor of length, $l$ and cross-sectional area, $A$ is given by $R=\rho \frac{l}{A}$ where $\rho$ is the resistivity.
Resistance increases with increase in resistivity, length of the resistor and decreases with decrease in its area. Resistivity is directly propoprtional to the temperature. So, when the temperature increases the resistance increases.