A copper rod, 5m long when heated through 20c, expands by 1mm. If a second copper rod, 2.5m long is heated through 5c, by how much will it expand?
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Correct Answer: Option B
Explanation:
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
Â
1
5(10)
=
l\(_2\) - l\(_1\)
2.5(5)
Â
l\(_2\)
-
l\(_2\)
=
2.5(5)
5(10)
=
1
4
=
0.25mm
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
Â
1
5(10)
=
l\(_2\) - l\(_1\)
2.5(5)
Â
l\(_2\)
-
l\(_2\)
=
2.5(5)
5(10)
=
1
4
=
0.25mm