Question

What is the least count of the vernier calipers? (A) Smallest division on the vernier scale. (B) difference of the smallest division on the main scale and the smallest division on the vernier scale. (C) sum of the smallest division on the main scale and the smallest division on the vernier scale. (D) smallest division on the main scale.

Short answer

The least count of vernier calipers is the difference between the smallest division on the main scale and the smallest division on the vernier scale. Therefore, the correct answer is (B).

Step-by-step solution

Understanding the scales of Vernier Calipers

Vernier calipers have two scales: the main scale and the vernier scale. The main scale is divided into millimeters while the vernier scale is fine-tuned to allow even more precise measurements.

Identifying the smallest division on both scales

The smallest division on the main scale is the smallest distance between two marks on the main scale, which usually represents 1mm. The smallest division on the vernier scale is the smallest distance between two marks on the vernier scale, and it is smaller than the smallest division on the main scale.

Determining the least count

The least count is the difference between the smallest division on the main scale and the smallest division on the vernier scale. This value represents the smallest length that can be accurately measured by the vernier calipers. So, the correct answer is: (B) Difference of the smallest division on the main scale and the smallest division on the vernier scale.

Key concepts

Least Count

The least count is a crucial concept when understanding how vernier calipers work. It represents the smallest measurement that can be accurately read using the instrument. This is important because it defines the precision level of the vernier calipers. To find the least count, you subtract the smallest division on the vernier scale from the smallest division on the main scale.

Here's a step-by-step way to determine it:

• Identify the smallest division on the main scale, which is usually 1mm in standard vernier calipers.
• Identify the smallest division on the vernier scale, which is smaller than that on the main scale.
• Calculate the least count by subtracting these two smallest divisions.

The resulting difference tells you the minimum measurable gap, indicating the instrument's accuracy.

Main Scale

The main scale of the vernier calipers is the backbone of the measurement process. It is marked and laid out in millimeters, providing a straightforward reference for measuring larger lengths. When you look at the vernier calipers, the main scale is the fixed portion that extends through most of the length of the tool.

Key features of the main scale include:

• Each division usually equals 1mm, offering straightforward readings for whole numbers.
• It serves as a base for the vernier scale to measure additional precision by overlapping with it.

Many times, the main scale by itself can't provide the micro-level accuracy required for precise tasks. That's where the vernier scale comes into play, enhancing the precision that the main scale initiates.

Vernier Scale

The vernier scale is what allows vernier calipers to achieve a higher level of precision than many other tools. It works in conjunction with the main scale to fine-tune measurements in smaller increments. This combination allows for much more accurate readings than relying on the main scale alone.

Key aspects of the vernier scale include:

• It is a sliding scale, moving over the main scale to read the in-between measurements.
• The divisions on the vernier scale are smaller than those on the main scale, typically fractions of a millimeter.
• By aligning its markings with those on the main scale, the vernier scale calculates those tiny differences essential for precise measurements.

The vernier scale is crucial for applications where minute accuracy is necessary, such as in engineering or scientific experiments, where even small deviations can matter significantly.