The microscope available in your biology lab has a converging lens (the eyepiece) with a focal length of 2.50 cm mounted on one end of a tube of adjustable length. at the other end is another converging lens (the objective) that has a focal length of 1.00 cm . when you place the sample to be examined at a distance of 1.30 cm from the objective, at what length l will you need to adjust the tube of the microscope in order to view the sample in focus with a completely relaxed eye

6.83 cm

Explanation:

Given data:

Focal length of the eye piece, = 2.50 cm

Focal length of the converging lens, f = 1.00 cm

distance of the object, p = 1.30 cm

Now,

we have the lens equation as:

q is the distance of the image

thus,

on substituting the values in the above equation, we get

or

q = 4.33 cm

now, the image is formed at the focal point of the eye piece,

therefore, the distance between the objective and the eyepiece, d = + q = 2.50 cm + 4.33 cm

or

d = 6.83 cm

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