The heat is flowing through a rod of length $50 cm$ and area of cross-section $5c{m^2}$. Its ends are respectively at ${25^o}C$ and ${125^o}C$. The coefficient of thermal conductivity of the material of the rod is $0.092 kcal/m×s×^\circ C$. The temperature gradient in the rod is
A${2^o}C/cm$
B${2^o}C/m$
C${20^o}C/cm$
D${20^o}C/m$
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A${2^o}C/cm$
a (a) Temperature gradient $\frac{{d\theta }}{{dx}} = \frac{{{{(125 - 25)}^o}C}}{{50\;cm}} = 2^\circ C/cm$
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