\(x = 2\, bps,\) which is decreasing after loading (i.e. \(x\, \downarrow\)) known tuning fork is loaded so \(n_A \,\downarrow\)
Hence \(n_A\downarrow -n_B = x\downarrow\) ... \((i)\) \(\rightarrow \) Correct
\(n_B -n_A \downarrow= x\downarrow\) ... \((ii)\) \(\rightarrow \) Wrong
==> \(n_B = n_A -x = 256 -2 = 254 Hz.\)
(હવામાં ધ્વનિની ઝડપ $340\, {ms}^{-1}$)