In the thermocouple, cold junction is at $0^{\circ}C$, hot junction is at $t^{\circ}C$. The graph drawn between thermo - emf (E) and temperature of the hot junction (t) is represented by the equation , $E=at+bt^2$. If $a = -224b$ the neutral and the inversion temperatures of the thermocouple respectively, in degree celsius are :

Question

$\begin {array} {1 1} (1)\;224,448 & \quad (2)\;112,224 \\ (3)\;448,224 & \quad (4)\;224,112 \end {array}$