Home › UP Board Class 10 › physics › c10lensformula › Per NCERT, what is 1 DIOPTRE — the SI unit of le…
Per NCERT, what is 1 DIOPTRE — the SI unit of lens power?
AHalf the focal length
BThe power of any lens whatsoever
CTwice the focal length
DThe power of a lens whose focal length is 1 metre
Answer & Solution
Correct answer: D. The power of a lens whose focal length is 1 metre
Per NCERT §9.3.8, 1 dioptre = lens with f = 1 m. So 1 D = 1 m⁻¹.
Related questions
Per NCERT, a combination of two lenses of power +2.0 D and +0.25 D in contact is equivalenPer NCERT, when several LENSES are placed in CONTACT, what is the NET POWER?Per NCERT, if a lens has POWER = −2.5 D, what is its FOCAL LENGTH — and is it convex or coPer NCERT, if a lens has POWER = +2.0 D, what is its FOCAL LENGTH — and is it convex or coPer NCERT, what is the POWER (P) of a LENS — and what is its SI unit?Per NCERT Example 9.4, for the same convex lens problem (f=+10, u=−15), what is the MAGNIFPer NCERT Example 9.4, a convex lens (f = +10 cm) has an object at u = −15 cm. What is thePer NCERT Example 9.3, a concave lens (f = −15 cm) forms an image at v = −10 cm. What is t