A lens has a power of -4 D. What is the type of lens?
Practice Questions
Q1
A lens has a power of -4 D. What is the type of lens?
Convex
Concave
Bifocal
Plano-convex
Questions & Step-by-Step Solutions
A lens has a power of -4 D. What is the type of lens?
Step 1: Understand what lens power means. Lens power is measured in diopters (D).
Step 2: Identify the sign of the lens power. In this case, the power is -4 D.
Step 3: Know that a negative power indicates a specific type of lens.
Step 4: Remember that a negative power means the lens is a concave lens.
Step 5: Conclude that since the power is -4 D, the lens is a concave lens.
Lens Power – The power of a lens is the reciprocal of its focal length in meters. A negative power indicates a concave lens, while a positive power indicates a convex lens.
Types of Lenses – Lenses can be classified as concave (diverging) or convex (converging) based on their shape and the sign of their power.
