Question

A uniform wire of length $l=5\pm 0.05cm$ and radius $r=0.5\pm 0.005cm$ has mass $m=0.4+0.004g$. The maximum percentage error in its density is

• A. 1
• B. 2
• C. 4
• D. 5.8

Answer 1

The correct option is C 4

$L{i}_3+2_{1}H\to 4_{2}H+4_{2}He$
$\Delta m=-(2\times 4\cdot 0026-2\cdot 0140-m)$
$m-5\cdot 9912$
$22\cdot 4=m-5\cdot 9912\times 931\cdot 5$
$0\cdot 024=m-5\cdot 9912$
$\Rightarrow m=6\cdot 0152amu$