Advertisements
Advertisements
प्रश्न
How is the power of a lens related to its focal length?
Advertisements
उत्तर
Power of lens (in D) = `1/"focal lenght (in metre)"`
1 diopter = `1/"focal lenght (in metre)"`
Or D = `(100 "cm")/"Focal length"`
APPEARS IN
संबंधित प्रश्न
The power of a lens is + 0.2 D. Calculate its focal length.
Name the type of lens whose power is positive.
The image of an object formed by a lens is real, inverted and of the same size as the object. If the image is at a distance of 40 cm from the lens, what is the nature and power of the lens ? Draw ray diagram to justify your answer.
How does focal length of a lens change when red light incident on it is replaced by violet light? Give reason for your answer.
According to Rayleigh’s scattering law, the amount of scattering of light is inversely proportional to the fourth power of its ______.
A convex lens with radii of curvature R1 = R2 is immersed in water. Assuming that the refractive indices of glass and water are 3/2 and 4/3 respectively, its focal length f1 in comparison to that in air, f, is ______.
The deviation of the incident light rays produced by a lens on refraction through it is a measure of its:
The power of a lens in dioptres is given by:
A greater numerical value of the power of a lens means:
If the refractive index of the lens material is less than that of the surrounding liquid (\[n_2 < n_1\]), then:
The power of a lens of focal length \[f = 0.5\,m\] is:
