For all case:

A$)$ Is heat transfer steady or transient $($unsteady state$)?$

B$)$ Is heat transfer one$-,$ two$-,$ or three$-$dimensional?

C$)$ Is there heat generation in the medium?

D$)$ Is the thermal conductivity of the medium constant or variable?

Problem $2$: The thin plate is in the $x-y$ plane. The left and right sides of the plate are perfectly insulated. The top surface of the plate is at $100C$ and the bottom is at $20C.$ Give the boundary equations for the plate.