Which of the following instruments is best for measuring the diameter of a thin constantan wire?
Answer Details
The micrometer screw gauge is the best instrument for measuring the diameter of a thin constantan wire. Micrometers are highly sensitive instruments that can measure small distances accurately. They are commonly used in precision engineering to measure the thickness of wires and the diameter of cylinders. The micrometer screw gauge has a spindle that moves as a thimble is turned, and the distance moved is indicated on a graduated scale. This allows for very precise measurements of small distances, such as the diameter of a thin wire. Callipers, metre rule, and vernier callipers are useful for measuring larger distances but are not as accurate as a micrometer screw gauge for measuring small distances.