# Focal Period of Lenses

Objective

The purpose of this research was to locate the central length of two converging lenses separately as well as find the focal period of combination of two converging lens. Another target was to study the image created by a converging lens in addition diverging contact lens.

Background

This experiment focused on a simple contact lens system. A basic lens can be described as piece of glassware that is circular on one aspect and flat on one more side, or perhaps spherical about both sides. There are two different types of lenses. A converging lens, also called a good lens, and a diverging lens, also called a negative zoom lens. A converging lens thicker middle region than leading and bottom, and the diverging lens has a skinnier mid-section. When a seite an seite ray goes through the zoom lens, the sun rays will be diffracted so that it will usually intercept the focal point. If a ray goes by through the optical center, you will see no diffraction. The three standard rules regarding the sun rays are: 1)Rays travelling seite an seite to the lens will diffract towards the focus 2)Rays traveling at optic centre could have no dispersion. 3)Rays travelling through the focus towards the contact lens will have a parallel dispersion to the plane. Focal duration f varies from lens to lens in fact it is characterized by:

1/f = 1/do + 1/di(equation 1)

perform represents the length of the object to the lens and di represents the length of the picture formed from your lens. Ordering for n, the formula becomes:

n = dido / (dВ¬i + do)(equation 2)

The theory behind the experiment Part I is the fact when an thing that is incredibly far away, the focal duration is equal to di. Applying equation one particular, this idea is recognized. When one particular is divided by perform (infinity), the significance will get nearer to zero, so it's possible to assume the limit as zero. In the event that this thought holds, the newest equation can become 1/f = 1/di. Hence f sama dengan di. Using this theory, the focal period of converging lens A was calculated. Also to support the idea, the same converging lens's focal point was worked out using a finite object. Then the percentage difference was calculated using the equation:

%difference = |(fwindow -- fexperimental)| / fwindow * 100%(equation 3) The key length to get the try things out was gathered using a thready graph. Formula 1 could possibly be rearranged in a linear formula.

1/do = 1/f + 1/di

1/do = -- do/dido + 1/f(equation 4)

The incline would be вЂ“do/di and the y-intercept would be 1/f according for this equation. Intended for Part 2 and 3, the equation that pertains the central length of two lenses to make a compound zoom lens system utilized.

1/fc sama dengan 1/fВ¬1 & 1/f2(equation 5)

Isolating this kind of equation intended for f1, the newest equation turns into:

f1 sama dengan fcf2 as well as (fВ¬2 -- fc)(equation 6)

Using chemical substance lens try things out and understanding the theory in back of equation 5, it was conceivable to calculate the focal length of a compound contact lens system by measuring the focal period of individual contacts. It is also feasible to measure the focal length of a single zoom lens and a compound contact lens system then simply find the focal entire unknown lens. This thought works intended for both converging and diverging lenses. Procedure

Part A: Single Converging Lens

Fig 1 Zoom lens experiment create

One convergent lens was placed between your light source and the white display screen on the optical rail. Both lens or the screen or perhaps both had been moved to concentrate a real picture of the crossed arrows on the screen. Then the distance from the object for the lens (do) and the photo distance to the lens (di) were scored and documented the image alignment. To measure the object size and the image size, a ruler was used and linear magnification was calculated. Same procedure was repeated to get five different object ranges. The focal length was determined by the y-intercept parts of the best match line by simply plotting graph of 1/di vs . 1/do.

Component C: Substance Lens (Two Converging Lenses)

Same steps from Portion A had been followed to look for focal span f2 of your second converging lens. Then...