A solid sphere when cut into two equal halves, two solid hemispheres will be formed Radius of sphere = $$frac{7}{2}$$ cm Increase in total surface area = $$(2 imes3pi r^2)-(4pi r^2)$$ = $$6pi r^2-4pi r^2=2pi r^2$$ = $$2 imesfrac{22}{7} imes(frac{7}{2})^2$$ = $$11 imes7=77$$ $$cm^2$$ => Ans - (A)