Question

which is accurate to measure length vernier capillar or screw gauge

Answer 1

its capillar according to me

Answer 2

Screw gauge is used to measure accurately than vernier caliper because least count of vernier caliper is 0.1mm but for screw gauge it is 0.01mm .
Screw gauge is used to measure very small object with small diameter like wire while in vernier caliper used to measure things like bob ,ball etc