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Length of a lens is the distance from the center of the lens to its principal focus?
Wiki User
∙ 13y ago
It is called the focal length. It is equal to 1/2 times r, and is positive on concave mirrors and negative on convex mirrors.
Wiki User
∙ 15y ago
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What is distance of principal focus from optical centre called?
Focal length
What is the principle focus of a concave mirror?
The refleted ray are meeting/intersecting at a point on the principal axis of the mirror.This point is called the principal focus of the concave mirror
What is meant by 'principal focus' in a convex mirror?
yes
Why does a converging lens behave as a burning glass?
Convex lenses focus parallel light rays from distant sources such as the sun to a single point on the principal axis of the lens. This point is called the principal focus of the convex lens. A source such as the sun is producing enough energy to heat a substance if it is placed at the principal focus point.
What happens to the image distance in the eye when you increase the distance of an object from the eye?
If everything is working as it should, the image distance in the eye never changes. The image always needs to focus on the retina, which doesn't move. This is where the lens comes in, specifically its ability to change its focal length. When the object distance changes, the focal length has to change, in order to keep the image distance constant. Muscles around the lens change the shape of the lens, in order to change its focal length.
The distance from the center of the lens to its principal focus is called the what?
Focal length
What is distance of principal focus from optical centre called?
Focal length
What is focal length?
focal length is the distance between your optic nerve and the retinsin lensethe distance between the optical and focus
What is a focal length?
it is the distance a lense is from an object in order for it to be in focus
What is the exact relation of the focal length to the center of curvature?
The focal length (a.k.a focus) is exactly half the length of the centre of curvature. ie. F = 1/2 C
How do you focus?
There is usually a knob on the binoculars for you to adjust the focus. When the focal length is adjusted, images of varying sharpness is obtained. Thus yu are adjusting the distance of the lens.
Define principal focus and principal aris?
principal focus is the ray which diverge at a point on the other side of the lensPrincipal Axis lens have two centre of culvature,the line passing through them and joining these centres is called principal axis.
How can you locate the focus of a coverging lens?
The focus of a converging lens can be found located by moving the object(source) from a large distance and getting it closer to the lens.As we go closer the size of the image which is obtained on a screen placed behind the mirror increases.At a certain point the size of the image and that of the object are equal.This point is known as the center of curvature.The focus is the midpoint of the center of curvature and the optical point.In other words the focal length is Radius of curvature/2
What is the principle focus of a concave mirror?
The refleted ray are meeting/intersecting at a point on the principal axis of the mirror.This point is called the principal focus of the concave mirror
The length of a hyperbola's transverse axis is equal to the the distances from any point on the hyperbola to each focus.?
difference between
What is meant by 'principal focus' in a convex mirror?
yes
How can we find focus of a lens?
Focus or focal length?
