The distribution of temperature T, at a particular instant, across a large concrete wall, 1 m thick, which is heated from one sideis given by the equation $$T = 150 - 80x + 16x^2$$, where the distance x is in meters and Tis in degree Celsius. Thermal conductivity of wall is 0.6 W/mK, area of cross section is 10 m?. The heat accumulated in unit time at this instant in the concrete wall is —

A

768 J/sec

B

384 J/sec

C

96 J/sec

D

192 J/sec