What is the power of lens in 40 cm?
Power of first lens of 40 cm ,therefore power is 100/f= 1/40=2.5 Dioptre …. since focal length is positive the lens is convex lens.
What is the power of a concave lens of focal length 40cm?
The focal length of a concave lens is equal to -2.5 D
Hence in the above case it is given that the focal length is 40cm or 0.4m. So the power =- 1/0.4= -2.5D the sign is used to determine the type of lens used.
What is power of lens of focal length of 20cm?
The power of a lens of focal length 20cm is 5D.
So both lenses have same convergence of refracted light.
What is power of lens of focal length of 20cm class 10?
so, 20 CM in metres= 20/100m=1/5 metres. power of a lens= 1/1/1/5=5 dioptres……..
What is the correct lens formula?
What is the Lens Formula? Answer: According to the convex lens equation, the lens formula is 1/f = 1/v + 1/u. It relates the focal length of a lens with the distance of an object which is placed in front of it and the image formed of that object.
What is the power of lens formula?
The power of a lens is defined as the reciprocal of its focal length in meters, or D = 1/f, where D is the power in diopters and f is the focal length in meters. Lens surface power can be found with the index of refraction and radius of curvature.
What is the power of convex lens of focal length 80 cm?
∴ p = 1 80 × 10 2 = 100 80 = 1.25 D .
What is the power of a concave lens of focal length 50cm?
Answer: The power of a lens is 1/focal length (measured in meters). So, 50 cm is 1/2 meter, so the power is -2; D stands for diopters, the unit of power for lenses. Hence, the power of a concave lens of focal length 50 cm is -2D.
What do concave lenses do?
A concave lens is a lens that possesses at least one surface that curves inwards. It is a diverging lens, meaning that it spreads out light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia).
What is the power of a lens of focal length 25 cm?
In this question it is given that the lens is convex, and its focal length is $25$ cm. First we will convert the focal length in meters. As it is a convex lens so its power is positive. Thus, the power of the lens is $+ 4D$.
Can a concave lens make a real image?
The concave lens will not produce real images. Real images are not formed by a concave lens since the rays passing through the concave lens diverges and will never meet.
What is the power of lens of focal length 10cm?
Answer: Convex lens have the ability to converge a parallel beam of light into a point. This point is called the focal point of the convex lens and the distance from the optical centre to the focal point is called the focal length. p = 10 D.