Which of the following properties of a long steel bar would alter if the bar were melted, recast into a cube and allowed to cool to its original temperature?
sensity
volume
specific heat capacity
electrical resistance
Explanation
No explanation available
Video Explanation
No video available
Post your Contribution
Discussions (6)
The answer should be D, because electrical resistance varies with Area of material. When the bar is casted to a cube the area will change, thereby changing the electrical resistance. Take note, resistance is inversely proportional to Area of conductor.
lets assume the steel bar is cylindrical
its area would be πr^2.
The area of the cube will be L^2.
To get the length of the cube, we will equate the vol of the cube and the bar, indicating that both volumes are equal, that is
L³ = πr2H.
Here is the correct explanation:
So far its d same long steel that was casted into a cube nd no mass was lost in d process,the volume remains the same,specific capacity(constant) remain and likewise the electical resistance.
The answer is **B. volume**.
When a long steel bar is melted and recast into a cube, the **shape** changes, but the **amount of material (mass)** and its **temperature** are the same. Here’s how each option is affected:
- **A. Density:** Density depends on mass and volume. Since only the shape changes (not the amount of steel), the density stays the same.
- **B. Volume:** Volume depends on the shape of the object. When the steel is reshaped from a bar to a cube, its volume may change because the steel could be compacted or expanded slightly during recasting. This makes **volume** the property that changes.
- **C. Specific Heat Capacity:** This property is about how much heat is needed to change the steel’s temperature. It’s a property of the material itself, not its shape, so it stays the same.
- **D. Electrical Resistance:** Resistance depends on material and length. Since changing the shape might affect the length and cross-sectional area, the electrical resistance could be different.
In summary, **volume** is most likely to change when the steel bar is melted and recast into a different shape.
