Answer:
The screw gauge is an instrument used for measuring accurately the diameter of a thin wire or the thickness of a sheet of metal. It consists of a U-shaped frame fitted with a screwed spindle which is attached to a thimble.
Explanation:
Measure the length of the coil with the help of a meter scale. The thickness of the wire can be found by dividing the length of the coil by the number of turns. Measure the diameter with callipers. Place an electrical wire between the jaws of a set of Vernier callipers. Slide the movable jaw around the cable without compressing the insulation and read the measurement where the line from the moving indicator meets the stationary scale for a diameter.