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The power of a lens is defined as the reciprocal of its ________.
Aperture
Radius of curvature
Focal length
Refractive index
Focal length
The power of a lens is defined as the measure of the degree of convergence or divergence of light rays falling on it. It is mathematically the reciprocal of the focal length when the focal length is measured in meters.
The power of a lens is defined as the measure of the degree of convergence or divergence of light rays falling on it. It is mathematically the reciprocal of the focal length when the focal length is measured in meters.
Think of a magnifying glass: a stronger lens (higher power) focuses sunlight into a tighter, hotter point very quickly, meaning it has a short focal length.
P = 1/f: Power and Focal length are inversely proportional, like a seesaw.
P=f(m)1тАЛ тАФ Power in Dioptre is the reciprocal of focal length in meters
P=f(cm)100тАЛ тАФ Power in Dioptre when focal length is in centimeters
A lens with a short focal length bends light rays more sharply than a lens with a long focal length. Since the ability to bend light is inversely proportional to the focal length, a smaller focal length results in a higher power. The unit of power is the dioptre (D), which is equivalent to 1/m.
The SI unit of power of a lens is the Dioptre (D).
For a convex lens, power is positive (+) because its focal length is positive.
For a concave lens, power is negative (тИТ) because its focal length is negative.
Power is additive: PtotalтАЛ=P1тАЛ+P2тАЛ+P3тАЛ+... for lenses in contact.
Allows for easy calculation of the combined power of multiple lenses in an optical system.
Does not account for spherical or chromatic aberration in a single value.
Prescription of spectacles for refractive errors like myopia and hypermetropia.
Design of optical instruments like microscopes and telescopes.
A lens of focal length 1 meter has a power of 1 Dioptre.
Option A (Aperture) relates to the light-gathering capability, not the focal power.
Option B (Radius of curvature) influences the focal length via the Lens Maker's Formula, but is not the definition of power.
Option D (Refractive index) affects the deviation of light, but is a property of the material, not the definition of power.
C is correct тАФ The power of a lens is the reciprocal of its focal length in meters.
Remember that power is always calculated in meters. If the focal length is given in cm, always divide 100 by the value to find power in Dioptres.