Please solve question no.8

Dear student,

The formula for measuring the length of an object using vernier callipers is as follows
Length of an object= main scale reading+ no of division of the vernier scale that is coinciding with the main scale X least count of vernier callipers.

Now in the above question,
Main scale reading is 3 this is because according to the convention when the vernier scale reading is between two readings of main scale then we always consider the smaller reading of the main scale.
Number of division of the vernier scale coinciding with the main scale is 6 because when we count the divisions on the vernier scale from 0 we will see that 6 division of the vernier scale is coinciding with the main scale.
Least of the vernier callipers is basically the minimum value on main scale divided by the total number of divisions on the vernier scale. So the least count of this vernier callipers will be 0.01cm.
Now the answer will be
length of rod= 3+ 0.01 X 6
                    = 3.06cm.

Thanks and regards.