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The formula for focal length is given byÊ1 divided by 1/a plus 1/b, where 'a' is the distance to a lamp or light source and 'b' is the distance to the wall. You find the focal length by placing a lens parallel to a white wall and focus a light source through the lens until one gets a clear image. The lamp has to be positioned so that it is close to the optical axis of the lens.

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How to find the focal length of a lens?

To find the focal length of a lens, you can use the lens formula: 1/f 1/do 1/di, where f is the focal length, do is the object distance, and di is the image distance. Measure the object and image distances from the lens, then plug the values into the formula to calculate the focal length.


How you can find focal length of plane?

The focal length of a plane is a fixed distance that defines its curvature or orientation. It does not change and can be specified by the designer or manufacturer. To find the focal length of a plane, refer to the technical specifications provided by the manufacturer or measure it directly using optical tools such as a focal length tester.


What is the relationship between field of view (FOV) and focal length in a focal length calculator?

In a focal length calculator, the field of view (FOV) and focal length have an inverse relationship. This means that as the focal length increases, the field of view decreases, and vice versa.


Length of a lens is the distance from the center of the lens to its principal focus?

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.


What is the positive lens is the same as?

The focal point F and focal length f of a positive (convex) lens, a negative (concave) lens, a concave mirror, and a convex mirror. The focal length of an optical system is a measure of how strongly the system converges or diverges light.


The distance from lens to focal point is called?

The distance from a lens to the focal point is called the focal length.


What happens if you decrease a telescopes eyepiece focal length?

The magnification of the telescope image is(focal length of the objective) divided by (focal length of the eyepiece).The focal length of the objective is fixed.Decreasing the focal length of the eyepiece increases the magnification of the image.(But it also makes the image dimmer.)


Which lens should be used in newton rings short or long focal length?

A lens with a long focal length is typically used in the Newton's rings experiment. This is because a longer focal length helps produce a larger, more distinct interference pattern, making it easier to observe and measure the rings.


How can you calculate magnification from the focal length of a lens?

To calculate magnification from the focal length of a lens, you can use the formula: Magnification (Image distance / Object distance) (focal length / focal length - object distance).


What would be the effect on magnification to increase the focal length of microscope and telescope?

The focal length of a telescope is directly related to the magnification in that the longer the focal length, the more magnification you get from the telsceope. How the focal length of a telescope relates to the length of the telescope itself depends on the design of the telescope. In a refracting telescope, the focal length is approximately the length of the telescope. In a reflecting telescope, the focal length is roughly two time the length of the telescope.


If the primary mirror of a telescope have a focal length of 225 centimeters and the eyepiece has a focal length of 7.5 millimeters then what is the magnifying power of the telescope?

The magnifying power of a telescope is the focal length of the scope in millimeters, divided by the focal length of the eyepiece in millimeters. Focal length of scope: 225cm=2250mm Focal length of eyepiece: 7.5mm 2250/7.5= 300X


What will decreasing a telescope's eyepiece focal length?

The magnification of the telescope image is(focal length of the objective) divided by (focal length of the eyepiece).The focal length of the objective is fixed.Decreasing the focal length of the eyepiece increases the magnification of the image.(But it also makes the image dimmer.)