The vernier caliper is more accurate that a plastic ruler. That's because the caliper is designed to be used and effectively read to measure small distances. And it does this better than a "regular" ruler because it has a vernier scale built into it. It's like an "amplified ruler" attached to the device that has increased accuracy. A link is provided to the Wikipedia article on the vernier caliper and to the one on the vernier scale. Check out the pictures and skim the details. You should be able to pick it up with a bit of thought.
A vernier caliper.
A caliper is more accurate.
A Vernier caliper is quite accurate and idiot proof. Part of its accuracy lies in its general ease of use.
Vernier Caliper are made with different materials even plastic vernier calipers are also available in market however generally stainless steel is used in making of vernier calipers
micrometer is more occurate.
Vernier calipers are used to measure length when quite accurate measurement is required, but not such accuracy as to require a micrometer.
accuracy in mm and inches
If the caliper is properly calibrated, then neither system is more accurate. Accuracy depends on the quality of the measuring, not the unit used.
quantity for measuring vernier caliper is what
A vernier caliper would be a good way, unless you need a more accurate measurement, in which case I might use a micrometer caliper.
To measure the inside diameter of a ring using a vernier caliper, you must use the small jaw or the internal jaw of a vernier caliper.
Most like a vernier caliper for accurate readings