A copper rod, 5m long when heated through 10c, expands by 1mm. If a second copper rod, 2.5m long is heated through 5c, by how much will it expand?
4mm
0.25mm
2mm
0.12mm
Correct answer is B
l\(_1\) = 5m, ΔT = 10c, l\(_2\) - l\(_1\) = 1mm
l\(_1\) = 2.5m, ΔT = 5c, l\(_2\) - l\(_1\) = ?
| using | α | = | l\(_2\) - l\(_1\)
l\(_1\)ΔT |
| 1
5(10) |
= | l\(_2\) - l\(_1\)
2.5(5) |
| l\(_2\) | - | l\(_2\) | = | 2.5(5)
5(10) |
= | 1
4 |
= | 0.25mm |