Given,
The supply voltage, V=121.7 V
The current drawn by the oven, I=5.7 A
From Ohm's law, the voltage across a load is directly proportional to the current through the load.
Thus the voltage across the oven is given by,
![V=IR](https://img.qammunity.org/2023/formulas/physics/college/qyxkyhe6das1rxrn37kfxfu7hnf52d3137.png)
Where R is the resistance of the oven when it is heated to the maximum temperature.
On rearranging the above equation,
![R=(V)/(I)](https://img.qammunity.org/2023/formulas/physics/college/58rgrjooatmu3x2o7lod65zu15oehjjsfu.png)
On substituting the known values,
![\begin{gathered} R=(121.7)/(5.7) \\ =21.35\text{ }\Omega \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/s80o6xtv941c7i9lmb94muyzn2wt2h7oa9.png)
Thus the resistance of the oven when it's fully heated is 21.35 Ω