Question

why acetylenic protons absorb upfield as compared to vinylic protons in proton nmr?

Answer 1

$\huge\underline\mathbb{ANSWER}$

Its protons absorb at higher field than that of almost all organic compounds, hence overlapping of signals does not occur. The protons of TMS are more shielded due to +I effect of Si which increases electron density around them, hence they absorb at upfield.