Earlier quoted context omitted.
sizeof(double) is not specific to any one programming language or architecture; it's determined by IEEE 754, an international, cross-language, cross-platform standard. Non-IEEE floating-point implementations are exceedingly rare nowadays (although they do exist). You're right about it being engineering, not computer science, but IMO it's reasonable to expect someone applying to a programming job (assuming this is wha…
Well.. C and C++ offer a wide variety of arithmetic types. Double precision is not required by the standards (except by the optional annex F of C99, covering IEEE 754 arithmetic), but on most systems, the double type corresponds to double precision. However, on 32-bit x86 with extended precision by default, some compilers may not conform to the C standard and/or the arithmetic may suffer from double-rounding issues.
I am actually kind of sick of the people that say these details are not important to being a good programmer. They absolutely are, knowing fundamentals of the machine, language, and environment that you are developing in is essential.