A rectangular piece of iron measuring 4 cm by 3 cm a...
A rectangular piece of iron measuring 4 cm by 3 cm at 20oC is heated until its temperature increases by 100 C. Calculate the new area of the metal. [Linear expansivity of iron is 1.2x 10−5 K−1]
12.0144 cm3
12.0346 cm3
12.0288 cm3
12.0173 cm3
Correct answer is C
Linear expansivity (α)
= A2−A1A1θ
Original Area(A1) = 4 x 3 = 12
New Area (A2) = ?
Temp. rise (θ) = 100oC
A2 - 12 = 1200 x 2 x 1.2 x 10−5
A2 - 12 = 2880 x 10−5
A2 - 12 = 0.0288
A2 = 12.0288 cm2