Question

The focal length of a small concave mirror is 3cm . In order to use this concave

mirror as a dentist’s mirror , the distance of tooth from this mirror should be

a) 5.5 cm b) 1.5cm c) 4.5 cm d) 3.5cm​

Answer 1

Answer:

b) 1.5cm

Explanation:

mark as brinilist

Answer 2

The distance of the tooth from the concave mirror should be Option (b) 1.5 cm

What is a dentist's mirror?

• Dentists use concave mirrors during tooth examination. This is because they are converging mirrors and reflect light to the focal point.
• Concave mirrors provide an enlarged image of the object focused, this is the reason that they are called converging mirrors.
• With the help of this mirror, dentists can see the enlarged image of the tooth and can identify cavities or infections.

Distance of tooth from the mirror:

• Here, the focal length of a small concave mirror is given as 3 cm.
• In order to form an enlarged image of the object by a concave mirror, the object must be placed within the focus.
• Similarly, the tooth has to be placed within the focus of 3 cm.
• Moreover, the distance of the tooth from the mirror should be less than the focal length of 3 cm.
• Among the options, option (b) 1.5 cm is less than 3 cm.
• Therefore, the distance of the tooth from this mirror should be 1.5 cm.