Answer:
5x
Step-by-step explanation:
Given that TM means Total Magnification and it is 500x.
Therefore, the formula to calculate for Total Magnification is by multiplying the eyepiece and the objective lenses.
The objective lenses are normally given as either 4x, 10x, 40x or where the microscope has a fourth objective lens, it is mostly labeled as 100x.
Hence, Total Magnification = eyepiece * objective lenses.
Assuming the objective lens is 100x
Then, 500x = eyepiece * 100x
=> eyepiece = 500x/100x = 5x.
Note: Usually, the mostly used ocular (eyepiece) magnifies ten times, which is written as 10x.