The distance between the pole and the principal focus is called the focal length (f) of the lens. The given focal length of the concave lens is f = -2 m. It is negative because a concave lens always has a negative focal length. The unit of power is dioptre
What is the power of a concave lens of focal length 200 cm?
The power of the lens is the reciprocal of the focal length of the lens. We know that, The focal length is the negative for the concave lens. Hence, The power of the concave lens is -0.5 D .
What is power of concave lens of focal length 50 cm?
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 will be the power of the concave lens of focal length 2m?
Thus, the power of this concave lens is, -0.5 dioptre .
What is the power of a concave lens of focal length 4 m *?
Answer: Power of a lens is equal to the reciprocal of its focal length. It is given by : So, the power of the lens is 0.25 D .
What is the power of a concave lens?
The power of the concave lens is negative . Concave lens surfaces have a virtual radius of curvature, and thus a negative curvature. Optical power is denoted by the same convention signs that are used for focal length.
How do you find the power of a concave lens?
- Given that, Focal length of the concave lens, f = 2 m.
- To find, Power of the lens.
- Solution, The relation between power and focal length of the lens is inverse. Power is given by : P = 1/f.
- f is the focal length of the lens and it is negative for concave lens.
What is the power of lens having focal length is 50 cm?
= 100/50 = 2 dioptre . The SI unit of power is dioptre.
What is the power of a concave lens of focal length 150 cm?
Hence P=1/1.50 m this is = +1.5D .
What is the power of a concave lens of focal length 500 cm?
Answer: POWER = 1/F (metres) » POWER = 100 / -75 = -(4/3) = 1.33 DIOPTRES .
What will be the power of a concave lens of focal length 0.5 m?
The algebraic sign of the magnifying power indicates whether the lens causes an incident pencil of parallel light rays to converge or to diverge. Thus, a diverging lens having a focal length of 1 m has a power of -1 diopter, and a converging lens of focal length 0.5 m has a power of two diopters .
Is power of convex lens positive?
The power of a lens is defined as the reciprocal of the focal length. ... Converging (convex ) lenses have positive focal lengths , so they also have positive power values. Diverging (concave ) lenses have negative focal lengths, so they also have negative power values.
What would be the power of concave lens which has a focal length of 0.5 m?
Answer: In the same way, a power of -2.0D means a concave lens of focal length -0.5m.
What is the power of concave lens of focal length 10 cm?
Thus, the powerof this convex lens is +10 dioptres which is also written as +10D. The plus sign with the power indicates that it is converging lens or convex lens.
What is the focal length of concave mirror?
Focal Length – The distance between the pole P of the concave mirror and the focus F is the focal length of the concave mirror. Thus, the focal length of a concave mirror can be estimated by obtaining a ‘Real image’ of a distant object at its focus, as shown in the figure.
What is the power of concave lens of focal length 10?
Hence, the power of the lens is 10 dioptre .
