The total magnification is 40x.

Quick scoop

To get the total magnification of a microscope, multiply the eyepiece magnification by the objective magnification.

Here, 10x eyepiece×4x objective=40x10x\text{ eyepiece}\times 4x\text{ objective}=40x10x eyepiece×4x objective=40x total magnification.

How it works

  • The eyepiece (ocular) acts as one lens system, usually 10x in student microscopes.
  • The objective lens (4x, 10x, 40x, etc.) provides the primary image magnification, which is then further enlarged by the eyepiece.

Extra example

  • A 10x eyepiece with a 40x objective gives 10×40=400x10\times 40=400x10×40=400x total magnification.
  • A 10x eyepiece with a 10x objective gives 10×10=100x10\times 10=100x10×10=100x total magnification.

TL;DR: 10x eyepiece × 4x objective = 40x total magnification.

Information gathered from public forums or data available on the internet and portrayed here.