The type of mirror used by dentists to inspect the teeth of patients is a

Step 1: Analyze the question We need to identify which mirror a dentist uses to look at a patient's teeth.

Step 2: Explain the concept

• Plane mirror: gives an image the same size as the object, so there is no magnification.
• Convex mirror: always gives a diminished, virtual image. It is used as a driving mirror and for security, because it widens the field of view.
• Concave mirror: when an object is placed inside the focal length (closer than F), it gives an erect, virtual, magnified image. It is used as a shaving mirror, a makeup mirror, in torches and headlamps as a reflector, and by dentists.
• Cylindrical mirror: not a standard mirror for this purpose.

Step 3: Apply to the dentist's case A dentist holds the small mirror close to the tooth, so the tooth is within the focal length of the mirror. A concave mirror then produces an enlarged, upright, virtual image. This lets the dentist see small details such as cavities and cracks clearly.

Step 4: Answer The mirror used is a concave mirror, which is option C.

Note on a common confusion: Many dental mirrors are sold as flat mirrors, which is why option A can tempt you. But for WASSCE, the expected answer is the concave mirror, because of its magnifying property.

Exam tip: Remember the uses this way:

• Concave = Close-up, magnifying (dentist, shaving, makeup)
• Convex = wide view (driving mirror, shop security)