Question

Focal length of objective lens and eyepiece lens are 1.25 cm and 5 cm and tube length is 26 cm. Find magnification of compound microscope in normal adjustment.

Hint:

For a compound microscope, the total magnification is the product of the magnifications due to the objective lens and the eyepiece. Use the tube length and focal lengths to calculate it.

Answer 1

Correct Answer: 104

Step 1: Use the magnification formula.
The magnification \( M \) of a compound microscope is given by: \[ M = \frac{L}{f_0} \times \frac{1}{f_e} \] Where \( L \) is the tube length, \( f_0 \) is the focal length of the objective lens, and \( f_e \) is the focal length of the eyepiece lens.
Step 2: Substitute the given values.
Substitute \( L = 26 \, \text{cm} \), \( f_0 = 1.25 \, \text{cm} \), and \( f_e = 5 \, \text{cm} \) into the formula: \[ M = \frac{26}{1.25} \times \frac{1}{5} = 104 \] Step 3: Conclusion.
The magnification of the compound microscope in normal adjustment is 104.