JEE Mains 06-Sep-2020 Shift 1 Solved Paper

A screw gauge has 50 divisions on its circular scale. The circular scale is 4 units ahead of the pitch scale marking, prior to use. Upon one complete rotation of the circular scale, a displacement of 0.5‌mm is noticed on the pitch scale. The nature of zero error involved, and the least count of the screw gauge, are respectively :