Department of Pre-University Education, KarnatakaPUC Karnataka Science Class 11

# When a Metal Wire is Stretched by a Load, the Fractional Change in Its Volume ∆V/V Is Proportional to - Physics

MCQ

When a metal wire is stretched by a load, the fractional change in its volume ∆V/V is proportional to

#### Options

• $\frac{∆ \text{l}}{\text{ l }}$

• $\left( \frac{∆ \text{ l }}{\text{ l }} \right)^2$

• $\sqrt{∆ \text{ l / l}}$

• none of these

#### Solution

$\frac{∆ \text{l}}{\text{ l }}$

$\text{ C . S . A . = A }$

$\text{ Length = l}$

$\text{ Volume of the wire V = Al }$

$\text{ Assuming no lateral strain when longitudinal strain occurs: }$

$\text{ Increase in volume: ∆ V = A ∆ l }$

$\Rightarrow \frac{∆ V}{V} = \frac{A ∆ \text{ l }}{\text{ Al }} = \frac{∆ \text{ l }}{\text{ l }}$

$\text{ So,} \frac{∆ V}{V} \text{ is directly proportional to } \frac{∆ \text{l}}{\text{ l }}$ .

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#### APPEARS IN

HC Verma Class 11, 12 Concepts of Physics 1
Chapter 14 Some Mechanical Properties of Matter
MCQ | Q 7 | Page 298