Question

The heat passing through the cross-section of a conductor, varies with time ‘t’ as Q(t) = αt – βt² + γt³. (α, β and γ are positive constants.) The minimum heat current through the conductor is

(1) \(\alpha - \frac{\beta^2}{2\gamma}\)

(2) \(\alpha - \frac{\beta^2}{3\gamma}\)

(3) \(\alpha - \frac{\beta^2}{\gamma}\)

(4) \(\alpha - \frac{3\beta^2}{\gamma}\)

Answer 1

Correct option is (2) \(\alpha - \frac{\beta^2}{3\gamma}\) 

Heat through cross section of rod