| Aim | The objective of this experiment is to measure the diameter of a small spherical/cylindrical body using vernier callipers with accuracy and precision. |
| Apparatus Required | Materials: Vernier callipers Small spherical/cylindrical body Paper or cloth to clean the surface of the body |
| Theory | Vernier calipers are widely used in industries and laboratories to measure dimensions of objects with high accuracy and precision. The vernier caliper consists of two jaws, one stationary and the other movable, which can be adjusted using a screw to measure the distance between them. The main scale is engraved on the stationary jaw and is used to read the measurement in millimeters or inches. The movable jaw has a vernier scale engraved on it, which slides over the main scale and is used to read the fraction of a millimeter or inch. To measure the diameter of a small spherical/cylindrical body, the jaws of the vernier caliper are opened and adjusted to a distance slightly greater than the diameter of the body. The body is then placed between the jaws, and the jaws are carefully closed until they lightly touch the body. The main scale and the vernier scale are then read to determine the diameter of the body. The precision of the measurement is determined by calculating the standard deviation of the measurements taken. Standard deviation is a measure of the amount of variation or dispersion of a set of data values from their mean or average. The smaller the standard deviation, the more precise the measurement is. It is important to note that the accuracy and precision of the measurement depends on several factors, such as the quality and calibration of the vernier caliper, the skill of the operator in taking the measurements, and the condition of the object being measured. Therefore, it is recommended to repeat the measurement several times and take an average to obtain an accurate and precise measurement. The least count of a Vernier Caliper is the smallest measurement that can be read and recorded using the instrument. It is determined by the distance between two consecutive graduations on the Vernier scale, and it is usually smaller than the distance between two consecutive graduations on the main scale. The formula for calculating the least count of a Vernier Caliper is given by: Least count = (1 main scale division)/(Total number of divisions on Vernier scale) For example, let’s assume that the main scale of a Vernier Caliper is graduated in millimeters (mm), and the Vernier scale has 10 divisions that cover a distance of 9 main scale divisions. In this case, the least count of the Vernier Caliper can be calculated as follows: Least count = (1 mm)/(10 divisions) = 0.1 mm Therefore, the least count of this Vernier Caliper is 0.1 mm, which means that the instrument can measure dimensions with a precision of 0.1 mm. If a measurement falls between two main scale graduations, the Vernier scale can be used to determine the fraction of the smallest division that the measurement falls within. By adding the main scale reading and the Vernier scale reading, the accurate measurement can be obtained. |
| Procedure | Clean the surface of the small spherical/cylindrical body using paper or cloth. Open the jaws of the vernier callipers and adjust them to a distance slightly greater than the diameter of the body. Place the body between the jaws of the vernier callipers and carefully close the jaws until they lightly touch the body. Read the main scale and the vernier scale to determine the diameter of the body. Record the measurement in a data table. Repeat the above steps at least three times to obtain an average diameter of the body. |
| Observation and Result | Observations: Record the readings from the main scale and vernier scale of the vernier callipers for each trial. Data Analysis: Calculate the average diameter of the small spherical/cylindrical body by adding the three measurements and dividing the sum by three. Calculate the precision of the measurement by calculating the standard deviation of the three measurements. Results: The average diameter of the small spherical/cylindrical body was determined to be [insert value and units]. The precision of the measurement was calculated to be [insert value and units]. The diameter of a small spherical/cylindrical body can be accurately and precisely measured using vernier callipers. It is important to repeat the measurement several times to ensure accuracy and to calculate the precision of the measurement. The results of this experiment can be used in various applications where the diameter of small objects needs to be determined with high accuracy and precision. |
