Structure of Alkyl Radicals Hyperconjugation

Which C-C bond would break first, the bond in ethane or that in 2,2-dimethylpropane  

In Summary Bond homolysis in alkanes yields radicals and free atoms. The heat required to do so is called the bond-dissociation energy, DH°. Its value is characteristic only for the bond between the two participating elements. Bond breaking that results in tertiary radicals demands less energy than that furnishing secondary radicals in turn, secondary radicals are formed more readily than primary radicals. The methyl radical is the most difficult to obtain in this way. 

---