\(H = i^2 Rt\)
\( \Rightarrow \) \(\frac{{{H_1}}}{{{H_2}}} = {\left( {\frac{{{i_1}}}{{{i_2}}}} \right)^2} \times \frac{{{R_1}}}{{{R_2}}}\, \Rightarrow \frac{{10}}{{{H_2}}} = {\left( {\frac{2}{1}} \right)^2} \times \frac{5}{4} \Rightarrow {H_2} = 2\,cal/sec\)