Steel bars each of length 3m at 28°C are to be used for constructing a rail line. If the linear expansitivity of the steel is 1 x (10^{-5}K^{-1}),what is the safety gap that must be left between the successive bars if the highest temperature expected is 40°C?
-
A.
1.2x (10^{-1}cm) -
B.
7.2x(10^{-1}cm) -
C.
6x(10^{-1}cm) -
D.
3.6x(10^{-1}cm) -
E.
1.8x(10^{-1}cm)
Correct Answer: Option D
Explanation
(alpha= frac{Delta{L}}{L_1Deltatheta}; Delta{L}=alpha{L_1}DeltathetaRightarrow 1.0times 10^{-5}times 3times (40-28)= 3.6times 10^{-2})