This problem asks for the approximate increase in the volume of a metallic sphere when its temperature increases.
$ V_0 = \frac{4}{3}\pi R^3 $
$ \beta \approx 3\alpha $
$ \Delta V = V_0 \beta \Delta T $
Substitute the expressions for $V_0$ and $\beta$:$ \Delta V = \left(\frac{4}{3}\pi R^3\right) (3\alpha) (\Delta T) $
Simplify the expression:$ \Delta V = 4\pi R^3 \alpha \Delta T $
The approximate increase in the volume of the sphere is $4\pi R^3 \alpha \Delta T$. This corresponds to Option B.
Match List I with List II :
| List I | List II |
| A. Young's Modulus | I. $\frac{\Delta d}{\Delta L} ( \frac{L}{d})$ |
| B. Compressibility | II. $\frac{FL}{A(\Delta L)}$ |
| C. Bulk Modulus | III. $-\frac{1}{\Delta P} (\frac{\Delta V}{V})$ |
| D. Poisson's Ratio | IV. $-P(\frac{V}{\Delta V})$ |
Choose the correct answer from the options given below :
Water flows in a streamline motion through a horizontal pipe of circular cross-section as shown in the figure. The pressure difference of water between P and Q is $15\text{ Nm}^{-2}$. The area of cross-section at P and Q are $40\text{ cm}^2$ and $20\text{ cm}^2$, respectively. The rate of flow of water through the pipe, in $\text{cm}^3\text{s}^{-1}$, is :
[Take density of water $= 1000\text{ kg m}^{-3}$]
The strain-stress plot for materials $A, B, C$ and $D$ is shown in the figure. Which material has the largest Young's modulus ? 