Units And Measurement

One main scale division of a Vernier calliper is equal to 1 mm and the number of divisions on the Vernier scale is 10 . When both the jaws touch each other, the Vernier scale shifts to the left of zero of the main scale in such a way that $4^{\text {th }}$ Vernier division coincides with a division of the main scale. If this Vernier calliper measures the length of the wire to be 1 cm , the actual length of the wire is :