Question

The magnifying power of a simple microscope can be increased if we use an eyepiece of
A. Higher focal length
B. Smaller focal length
C. Higher diameter
D. Smaller diameter

Answer 1

We know that the eyepiece of the simple microscope is a biconvex lens. If an object is placed at the focus of the lens then the image is virtual and large in the size.

Complete step-by-step solution:
We know that in a simple microscope, the eyepiece is a biconvex lens. If $D$ is the least distance of the distinct distance and $F$ is the focal length of the convex lens then the magnifying power $M$ of a simple microscope is given as-
$M = 1 + \dfrac{D}{F}$
From the above formula, it is clear that if the value of Focal length is decreased then the value of magnifying power is increased or vice-versa. So, if the focal length of the eyepiece decreased, then the magnifying power was increased.
Hence, the magnifying power of a simple microscope can be increased if we use an eyepiece of smaller focal length.
Therefore, option B is correct.

Additional Information: - Single microscope can be described as a device that uses a single lens for magnification. In a simple microscope single lens is used while in a compound microscope several lenses are used to enhance the magnification of an object. The simple microscope works on the principle in which a tiny object is placed within the focus of the lens then a virtual erect and magnified image of the object is formed which is at the least distance of distinct vision from the eye held close to the lens.

Note:- The simple microscope has a single lens which is biconvex. The compound microscope has multiple lenses. The object which is seen through the microscope should be placed within the focus of the eye piece.