Flashcards
Reflection and Refraction of Light and Lenses and the eye
Flashcards do conjunto (30)
- 1CONVERGING LENSMakes rays converge
- 2DIVERGING LENSMakes rays spread out
- 3REFRACTION-AIR TO GLASSTOWARDS NORMAL
- 4REFRACTION-GLASS TO AIRAWAY FROM NORMAL
- 5REFRACTIONCHANGING DIRECTION OF WAVES WHEN THEY TRAVEL ACROSS A BOUNDARY FROM ONE MEDIUM TO ANOTHER
- 6REFRACTIVE INDEXsini ÷ sinr
- 7i = 10 r = 6.5 n = ?n = 1.54
- 8i = 20 r = 13 n = ?n = 1.52
- 9REFRACTIVE INDEX1 ÷ sinc
c = critical angle - 10MagnificationHi ÷ Ho
- 111 ÷ (d from o to l) + 1 ÷ (d from l to i)= 1 ÷ focal length
- 12IrisControls amount of light entering the eye
BRIGHT LIGHT-EXPANDS (LETS IN SMALL AMOUNT)
DIM LIGHT-CONTRACTS (LETS IN LARGE AMOUNT) - 13LensFocuses light onto retina
- 14retinaLight sensitive cells around the inside of the eye
- 15Optic nerveTransfers signals from retina to brain
- 16Eye musclesMove eye
- 17Ciliary musclesfine focusing.
CONTRACT AND SQUEEZE LENS SO ITS FATTER TO FOCUS ON CLOSE UP THINGS.
RELAX LENS TO SEE THINGS FAR AWAY - 18Pupilwhere light enters eye
- 19CorneaFocuses the view on Retina
- 20—
- 21—Myopia-Short sighted
Eye lens too strong
Fix with diverging lens
- 22—Long sighted
Eye lens too weak
Fix with converging lens
- 231 ÷ Focal length in metres= power of lens
- 24TOTAL INTERNAL REFLECTIONOCCURS WHEN THE ANGLE OF INCIDENCE OF A LIGHT RAY IN A TRANSPARENT MEDIUM IS GREATER THAN THE CRITICAL ANGLE.
- 25AN EXAMPLE OF SOMETHING THAT USES TOTAL INTERNAL REFLECTIONENDOSCOPE
- 26HOW ENDOSCOPE WORKSTWO BUNDLES OF OPTIC FIBRES.
INSERTED IN THROAT
ONE SHINES LIGHT
ONE CARRIES LIGHT BACK TO THE OBSERVER.
LENS FORMS AN IMAGE ON THE END OF FIBRES.
PROCESS-TOTAL INTERNAL REFLECTION - 27THE IMAGE PRODUCED BY A DIVERGING LENS ISVIRTUAL
- 28WHEN THE OBJECT IS NEARER TO THE LENS THAN THE PRINCIPAL FOCUS WITH A CONVERGING LENS THE IMAGE PRODUCED ISVIRTUAL
- 29POSITION AND NATURE OF IMAGE FORMED BY A LEN DEPENDS ONFOCAL LENGTH
DISTANCE FROM OBJECT TO LENS - 30—