Two resistors of resistance, 100Ω and 200Ω are connected in...

Heat produced in resistor $H = \dfrac{{V}^{2}}{R}t$

Here, the potential is constant tor parallel combination.

Here ${R}_{1} = 100Ω$, ${R}_{2} = 200Ω$

$\dfrac{{H}_{1}}{{H}_{2}} = \dfrac{{R}_{2}}{{R}_{1}} = \dfrac{200}{100} = 2: 1$