CBSE Class 10 Answered
The given microscope has eyepiece of magnification 15X and objective lens of magnification 10X.
Therefore, the total magnification = 15 × 10 = 150X
Eyepiece has least count 10 mm and the cell measured 60 divisions on the eyepiece scale. This means that the field of view or the area occupied by the cell under the given magnification is 60 × 10 = 600 mm.
In order to calculate the actual size of the object, we need to divide the area occupied by the cell with the total magnification of the compound microscope.
Therefore,
Actual size of the cell = Area occupied (field of view)/Total magnification
= 600/150
= 4 mm
= 0.004 mm
The approximate size of the cell is 4 mm.