Which term describes the Vernier scale graduation used for reading main-scale measurements?

Which term describes the Vernier scale graduation used for reading main-scale measurements?

• A. Zero graduation
• B. Main scale graduation
• C. Vernier scale graduation for main scale reading
• D. Dial graduation

Answer: (C)

Reading with a Vernier instrument hinges on using the Vernier graduations that interpolate between main-scale marks. The Vernier scale graduation used for reading main-scale measurements is exactly that set of Vernier graduations—the ones on the Vernier scale used to determine the fractional part of the main-scale reading. When a line on the Vernier aligns with a line on the main scale, the number on the Vernier indicates how far past the last main-scale division you are, giving a more precise measurement than the main scale alone. The other terms refer to the zero line, the main-scale divisions themselves, or the dial, none of which describe this interpolating Vernier graduations.

Reading with a Vernier instrument hinges on using the Vernier graduations that interpolate between main-scale marks. The Vernier scale graduation used for reading main-scale measurements is exactly that set of Vernier graduations—the ones on the Vernier scale used to determine the fractional part of the main-scale reading. When a line on the Vernier aligns with a line on the main scale, the number on the Vernier indicates how far past the last main-scale division you are, giving a more precise measurement than the main scale alone. The other terms refer to the zero line, the main-scale divisions themselves, or the dial, none of which describe this interpolating Vernier graduations.