What best describes the battery in this picture? a) an electrolytic cell that has spontaneous half reactions b) multiple voltaic cells that have spontaneous half reactions c) an electrolytic cell that has nonspontaneous half reactions d) multiple voltaic cells that have nonspontaneous half reactions

is there multiple choice answers?

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.