Question

While measuring the length of a rod by vernier calipers the reading on main scale is $6.4cm$ and the $8^{th}$ division on the vernier is in line with a main scale division. If the least count of the vernier is $0.01cm$ and the zero error is $-0.04cm$ , the length (in $cm$ ) of the rod is $\frac{a}{100}$ . Find $a$ .

Answer 1

Answer: 652

Length of the rod $=$ observed reading $-$ zero error
$=$ (Main scale division $+$ Vernier scale division $\times L.C.$ ) $-$ Zero error
$=\left(6.4+8\times 0.01\right)-\left(-0.04\right)$
$=6.4+0.08+0.04=6.52cm$