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haha.. mmmfff,, with my quizzes, summative tests and periodic test.. mmfff.. wud u tell me if i cud paz my physics subject!?!.. mfff.. i hope so.. but if not.. itz okey ill just exert mur effort to the next grading.. and it will be okey to my mom if i wud get a low grade or passing grade rather coz i was explained it to her why wud that happen.. XD
pray for me!?!.. wahaha.. "if u exerted 50% to my subject..then exert 200%.. in the next grading".. wooowww.. wud believe that.. were not exerting effort to the subject.. to tell ye the truth diz is dah only subject,, dat i listen attentively and diz is the only subject that i exert large effort just to be able to passs.. weeeooww!!!..
!!get ready for the next headaches!! XD
!!hapi now!!
tests..testss.. testsss.. XD
1st summative--> 32/70; !!yakz
2nd summative-->34.75/70; !!way better
Periodic Test-->28/60; !!eeiww
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tests are done.. weee.. relaxed and enjoy now!!!.. weeee.. XD
well.. new grading new headaches!?!.. hehe.. anywayz before thinking
of dat headaches. ill first relaxed my mind from that harsh tests
and requirements.. ill first enjoy now my time to hangouts and leisures..
and then go back to the crazy world of school..XD
FIBER OPTICS
You hear about fiber-optic cables whenever people talk about the telephone system, the cable TV system or the Internet. Fiber-optic lines are strands of optically pure glass as thin as a human hair that carry digital information over long distances. They are also used in medical imaging and mechanical engineering inspection.
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Fiber optics (optical fibers) are long, thin strands of very pure glass about the diameter of a human hair. They are arranged in bundles called optical cables and used to transmit light signals over long distances.
If you look closely at a single optical fiber, you will see that it has the following parts:
Core - Thin glass center of the fiber where the light travels
Cladding - Outer optical material surrounding the core that reflects the light back into the core
Buffer coating - Plastic coating that protects the fiber from damage and moisture
Hundreds or thousands of these optical fibers are arranged in bundles in optical cables. The bundles are protected by the cable's outer covering, called a jacket.
Optical fibers come in two types:
Single-mode fibers
Multi-mode fibers
Single-mode fibers have small cores (about 3.5 x 10-4 inches or 9 microns in diameter) and transmit infrared laser light (wavelength = 1,300 to 1,550 nanometers). Multi-mode fibers have larger cores (about 2.5 x 10-3 inches or 62.5 microns in diameter) and transmit infrared light (wavelength = 850 to 1,300 nm) from light-emitting diodes (LEDs).
Some optical fibers can be made from plastic. These fibers have a large core (0.04 inches or 1 mm diameter) and transmit visible red light (wavelength = 650 nm) from LEDs.
CAMERA and HUMAN EYE
take a luk at dat picz.. nd u wud see the similarities between the human eye nd a simple camera.. XD
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The human eye is a wonderful instrument, relying on refraction and lenses to form images. There are many similarities between the human eye and a camera..
Light is excluded or permitted to enter by the eyelids, the equivalent of the camera shutter. The iris contains the variable opening, the pupil which regulates the amount of light entering and is the aperture of a camera. The diaphragm contains the aperture of the camera, so it is similar to the iris, which contains the pupil. The lens of the eye is a biconcave, transparent structure which is responsible for focusing. The innermost coat, the retina, lies behind the lens. It contains the optic disk, or blind spot, which is the junction of nerve fibers passing to the brain. It is the counterpart of the film in a camera. The film stores the photographic chemical record of data. The lens of the camera draws the light into the camera and focuses it on the film plane. To prevent the blurring of images by internal reflection, the inner walls of the camera-- the choroid layer in a human eye-- are painted black.
now ye know!!.. XD
CONVEX MIRROR
and what if you place a object infront of an convex mirror.. where is the image formed?
..steps..
1.Pick a point on the top of the object and draw two incident rays traveling towards the mirror.
2.Using a straight edge, accurately draw one ray so that it travels towards the focal point on the opposite side of the mirror; this ray will strike the mirror before reaching the focal point; stop the ray at the point of incidence with the mirror. Draw the second ray such that it travels exactly parallel to the principal axis. Place arrowheads upon the rays to indicate their direction of travel.
[..Once these incident rays strike the mirror, reflect them according to the two rules of reflection for convex mirrors.
The ray that travels towards the focal point will reflect and travel parallel to the principal axis. Use a straight edge to accurately draw its path. The ray which traveled parallel to the principal axis on the way to the mirror will reflect and travel in a direction such that its extension passes through the focal point. Align a straight edge with the point of incidence and the focal point, and draw the second reflected ray. Place arrowheads upon the rays to indicate their direction of travel. The two rays should be diverging upon reflection..]
3.Locate and mark the image of the top of the object.
The image point of the top of the object is the point where the two reflected rays intersect. Since the two reflected rays are diverging, they must be extended behind the mirror in order to intersect. Using a straight edge, extend each of the rays using dashed lines. Draw the extensions until they intersect. The point of intersection is the image point of the top of the object. Both reflected rays would appear to diverge from this point. If your were to draw a third pair of incident and reflected rays, then the extensions of the third reflected ray would also pass through this point. This is merely the point where all light from the top of the object would appear to diverge from upon reflecting off the mirror. Of course, the rest of the object has an image as well and it can be found by applying the same three steps to another chosen point
>>image formed..
location:behind the mirror..{virtual}
di..{negative}
magnification..{positive}
position..{upright}
converging lens
1.Ray #1
..runs parallel to the axis until it reaches the lens; then it refracts through the lens and leaves along a path that passes through the lens' principal focus
2.Ray #2
..runs straight through the center of the lens never bending
3.Ray #3
..first passes through the focus until it reaches the lens; then it refract through the lens and leaves parallel to the lens' axis on the other side of the lens
4.the intersection of this rays.. this were the image is located
!!wee sorry for the not clear pics..ill jhuz post a new one,, clear nd easy to see!!
CONCAVE MIRROR
when an object is place in front of a concave mirror.. do you know where is its image formed?!?.. XD
here's the steps how to locate the object's image.. XD
1.Pick a point on the top of the object and draw two incident rays traveling towards the mirror.
2.Using a straight edge, accurately draw one ray so that it passes exactly through the focal point on the way to the mirror. Draw the second ray such that it travels exactly parallel to the principal axis. Place arrowheads upon the rays to indicate their direction of travel.
[..Once these incident rays strike the mirror, reflect them according to the two rules of reflection for concave mirrors.
The ray that passes through the focal point on the way to the mirror will reflect and travel parallel to the principal axis. Use a straight edge to accurately draw its path. The ray which traveled parallel to the principal axis on the way to the mirror will reflect and travel through the focal point. Place arrowheads upon the rays to indicate their direction of travel. Extend the rays past their point of intersection..]
3.Mark the image of the top of the object.
The image point of the top of the object is the point where the two reflected rays intersect. If your were to draw a third pair of incident and reflected rays, then the third reflected ray would also pass through this point. This is merely the point where all light from the top of the object would intersect upon reflecting off the mirror. Of course, the rest of the object has an image as well and it can be found by applying the same three steps to another chosen point.
4.Repeat the process for the bottom of the object.
>>image characteristics..
infront of the mirror.. {real image}
di..{positive}
magnification..{negative}
position..{inverted}
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