Percentage Change in Length of a Rod – Rankers Physics

Thermal Expansion: Practice Problem & Solution

The percentage change in length of 1 m iron rod if its temperature changes by 100ºC is (\(\alpha\) for iron is \(2 \times 10^{-5}/\text{ºC}\))
0.2%
0.3%
0.5%
0.9%

Short Solution (Best for NEET):

To solve this problem, we apply the core principles of Thermal Expansion. Understanding the underlying formula is key to arriving at the correct answer below:

The percentage change in length is given by \(\frac{\Delta L}{L} \times 100 = \alpha \Delta T \times 100 = (2 \times 10^{-5}) \times 100 \times 100 = 0.2%\).

Leave a Reply

Your email address will not be published. Required fields are marked *

Similar Practice Questions

Explore conceptually related problems to test your knowledge.

1. Assertion (A): On sudden expansion a gas cools. Reason (R): On sudden expansion, no heat is supplied to system and hence gas does work at the expense of its internal energy.  
2. Assertion (A): Specific heat capacity of a substance in \(\text{cal/g}^{\circ}\text{C}\) is greater than its specific heat capacity in \(\text{cal/g}^{\circ}\text{F}\). Reason (R): Magnitude (temperature difference) of \(1^{\circ}\text{C}\) is greater than the magnitude of \(1^{\circ}\text{F}\).  
3. Assertion (A): Molar heat capacity at constant pressure can be less than molar heat capacity at constant volume. Reason (R): \( C_p - C_V = R \) is valid only for ideal monoatomic gas.  
4. Assertion (A): Molar heat capacity of a gas in any process can have any value ( -infty ) to ( +infty ). Reason (R): Molar heat capacity of a gas in an isothermal process is ( infty ).  
5. Assertion (A): At \(0K\), pressure of an ideal gas becomes zero. Reason (R): At \(0K\), according to ideal gas equation \(PV = 0\), volume cannot be zero hence pressure should be zero to satisfy this equation.