Most favourable conditions for electrovalency are (a) Low charge on ions, large cation and small anion
(b) High charge on ions, small cation and large anion.
(c)X High charge on ions, large cation and small anion
(d) Low charge on ions, small cation and large anion
bila da

I think

Explanation:

low charge of ions, large cation and small anion

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.