Question

The unit of magnification is:
A. m
B. m²
C. m^-1
D. It has no units

Answer 1

Hint: Here, we will proceed with the overview of the term magnification, its definition and the formula. Take the ratio between image distance and the object distance.

Complete step by step solution:
Magnification is the ratio of the distances that is the image distance to the object distance. Also, it can be defined as the ratio of the image height to the object height.
The magnification can be expressed as
$
  M = \dfrac{{{D_i}}}{{{D_o}}} \\
  M = \dfrac{{{H_i}}}{{{H_o}}} \\
 $
Where,
M is the magnification
D_i is the image distance
D_o is the object distance
H_i is the Height of the image
H_o is the Height of the object

Magnifying glass or the microscope is used for the magnification. It is focussed on objects and it produces an image. If the magnification becomes the negative, it means that the image is inverted.
When two media is different on the two sides of the lens, magnification is expressed as,
$M = \dfrac{{n{D_i}}}{{n'{D_o}}}$
Where,
n is the refractive index

Since, magnification is the ratio of the two lengths, and therefore it has no units.

Hence, from the given multiple choices, option D is the correct answer.

Note: Units are the standards of the measurement of the physical quantities. Physical quantities are divided into two types. 1) Fundamental units and 2) Derived Units. To measure the fundamental physical quantities length, mass and time we have three systems of the units. They are $1)$ CGS system (Centimetre, gram, second) $2)$MKS System (Metre, Kilogram, Second) 3) System International (SI) Unit.