Why do vernier caliper is more precise than a ruler?

A vernier caliper is more precise than a ruler because it utilizes a sliding scale that allows for measurements to be read to a finer degree, typically up to 0.01 mm, compared to a standard ruler that usually offers precision of only 1 mm. The dual scale on the caliper, consisting of a main scale and a sliding vernier scale, enhances measurement accuracy by enabling users to interpolate values between the smallest divisions. This capability makes vernier calipers ideal for measuring small dimensions with greater accuracy in various applications.