The last line should say 40x objective lens instead of 400x

The average diameter of a Streptococcus mitis cell is 0.92 mum. How many of these cells, if lined up end-to-end, would fit across the field diameter when viewed under a microscope using the 10times ocular and the 400times objective? (Recall that TM times FD (mm) 200 for our class microscopes.)

Solution

Answer:

They didn\'t mentioned the measuring scale of the microphone in 10X and 40X. However, for any instance 10X is having an unit of 2mm. So in that particular region under 10X, lined up cells will be 2000/0.00092= 21739103. All you have to multiply the total length of desired line with this unit (for instance 2mm here).