how do you verify experimentally that the focal length of a convex lens?
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vi) When the lens is dipped to a height which is greater than the focal length of lens in air, we are able to see the image. Showing that focal length of the lens has increased water. vii) From this we conclude that the focal length of a convex lens is increased when it is kept in water.
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Accepted Answer: The focal length of the concave mirror does not change when it is immersed in water because focal length of a mirror does not depend upon the refractive index of the medium. ... Therefore, when a convex lens is dipped into water, its focal length increases.
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Focal Length. The focal length ( f ) is the distance from a lens or mirror to the focal point ( F ). This is the distance from a lens or mirror at which parallel light rays will meet. ... Light rays that are parallel to each other, but not to the optical axis, will meet on the focal plane.
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The distance from the lens to the focal point is called the focal length. For converging lenses, the focal length is always positive, while diverging lenses always have negative focal lengths.
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The focal length ( f ) is the distance from a lens or mirror to the focal point ( F ). This is the distance from a lens or mirror at which parallel light rays will meet. (right) a concave mirror. Note that a lens has a focal point on both sides of the lens axis.
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Convex lens converges incident rays. Hence the rays to converge at a point in front of the lens. So image distance is positive here. We can easily clarify that the focal length is positive direction for a Convex lens while negative with concave lens.
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To summarize, though, one commonly quoted focal length of the eye is 17mm (this is calculated from the Optometric diopter value). The more commonly accepted value, however, is 22mm to 24mm (calculated from physical refraction in the eye). In certain situations, the focal length may actually be longer.
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The focal length ( f ) is the distance from a lens or mirror to the focal point ( F ). This is the distance from a lens or mirror at which parallel light rays will meet. Light rays that are parallel to each other, but not to the optical axis, will meet on the focal plane. ...
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Due to symmetry, there are two principal focus points. Focal length is the distance between the principal focal point and the optical centre of the lens (located on the optical axis and in the "middle of the lens).
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7. A double concave lens has a focal length of -10.8 cm.
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The focal length is f = 1/P = 3R/2; this is the distance of the focal planes out from the centre of the sphere, which is R/2 in front of and behind it. This can be checked directly.
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f, the focal length, is positive for a concave mirror, and negative for a convex mirror. When the image distance is positive, the image is on the same side of the mirror as the object, and it is real and inverted. When the image distance is negative, the image is behind the mirror, so the image is virtual and upright.
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The distance from the lens to the focal point is called the focal length. For converging lenses, the focal length is always positive, while diverging lenses always have negative focal lengths. However, these conventions are arbitrary, and physicists could just as easily have made the signs opposite.
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The lens itself is gigantic. Imagine a telephoto lens 30 feet long! That's 8.8 meters. It has a fixed aperture of f/14.7.
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The focal length of a mirror is given by f2​=v1​−u1​.
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The distance from the pole to the center of curvature is called (no surprise, I hope) the radius of curvature (r). The distance from the pole to the focal point is called the focal length (f). The focal length of a spherical mirror is then approximately half its radius of curvature.
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The focal length of the concave mirror is given as f. As per the sign convention for mirror, the focal length is taken as negative as it is measured opposite to the direction of light. Hence, focal length f = -f. The distance of the object from the principal focus is p.