The focal length of a lens of power −4D is
Question
The focal length of a lens of power −4D is
Solution
The power of a lens is given by the formula:
P = 1/f
where: P is the power of the lens in diopters (D), f is the focal length of the lens in meters (m).
In this case, the power of the lens is -4D. We can rearrange the formula to solve for the focal length:
f = 1/P
Substituting the given power into the formula gives:
f = 1/(-4D) = -0.25m
So, the focal length of a lens of power -4D is -0.25 meters. The negative sign indicates that the lens is diverging.
Similar Questions
A lens has a refractive power of −1.50 D. What is its focal length?
A doctor has prescribed a corrective lens of power +1.5 D. What is the focal length and nature of the lens?
Two lenses of power +2D and -4D. What is the nature of the focal length of each lens An object is placed at a distance of 100 cm from each of the above lenses. Calculate (i) image distance (ii) magnification in each of the two cases
he power of a lens is - 5D. Name the type of lens
Define power of a lens. What is its unit? One student uses a lens of focallength 50 cm and another of –50 cm. What is the nature of the lens and itspower used by each of them?
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.