What is the focal length of concavo-convex lens?

What is the focal length of concavo-convex lens?

The focal length of a concave-convex lens of radii of curvature 5 cm and 10 cm is 20 cm.

Why power of convex lens is positive?

Answer. The power of a convex lens is positive as a convex lens has a positive focal length, while the power of a concave lens is negative as concave lens has a negative focal length. It is because focal length of convex lens is +ve and. Therefore power of convex lens is positive.

What is convex radius?

Radius of curvature (ROC) has specific meaning and sign convention in optical design. A spherical lens or mirror surface has a center of curvature located either along or decentered from the system local optical axis. If the vertex lies to the left of the center of curvature, the radius of curvature is positive.

Is the focal length of a concave lens is positive therefore its power should be?

The focal length of a concave surface is negative, whereas the focal length of a convex surface is positive. Therefore, for a lens, the power of a concave and convex lens is negative and positive respectively.

Is power of concave lens positive?

The power of a lens is defined as the reciprocal of the focal length. Lens power is measured in dioptres (D). 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 is the power of a convex lens of focal length 0.5 m?

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.

What is the power of lens of focal length cm?

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 is the focal length of a lens whose power is 1.5 D?

Solution. = 1/+1.5 = 0.67 m. As the power of the lens is (+ve), the lens is converging.