A student uses a standard Vernier calliper ( 1 main scale division = 1 mm, 10 Vernier scale divisions = 9 main scale divisions) which is known to have a negative zero error. The actual thickness of a glass slab is exactly 3.20 cm. When measuring the slab, the main scale reads 3.1 cm and the 7^ th Vernier division coincides with a main scale division. Which Vernier division coincides with a main scale division when th

Step-by-step solution

The least count (LC) of the standard Vernier calliper is: LC = 1 mm - 0.9 mm = 0.1 mm = 0.01 cm The observed reading during the measurement is: Observed reading = MSR + ( VSR LC ) = 3.1 cm + (7 0.01 cm ) = 3.17 cm The relationship between actual thickness, observed reading, and zero error is: Actual reading = Observed reading - Zero error 3.20 cm = 3.17 cm - Zero error Zero error = 3.17 cm - 3.20 cm = -0.03 cm For a negative zero error, the zero of the Vernier scale is to the left of the main scale zero. The magnit