REFRACTION OF LIGHT (P 33 01) Apparatus: GSN 246 POG 465 POG 461 POG 550.01 KAL 60/5A Adhesive Magnetic Board Ray box, 6V 20W Diaphragm and slits Cuvette 1 1 Connecting lead Power supply Beaker glass Procedure:   Fill the cuvette with water Setup the ray box as shown A light ray emitted by the ray box hits the surface where the air meets the water at an angle of incidence of about 30° It may, on the one hand, be observed that the light is refracted toward the perpendicular and, on the other, that it is partially reflected from this surface The light ray hits the surface where the water meets the air at an angle of incidence  It may be observed that the light ray is refracted from the perpendicular at angle and partially reflected at angle .The reflected ray of light returns to the surface where the water meets the air Here again refraction from the perpendicular and partial reflection occur In addition, it may be seen that the ray proceeding from the light and the one leaving the cuvette below are shifted The beaker with water represents a plate with parallel faces Optics Panel Type | TOTAL REFLECTION IN WATER (P 33 02) Apparatus: GSN 246 POG 465 POG 461 POG 550.01 KAL 60/5A    Adhesive magnetic board Ray box, 6V 20W Diaphragm and slits Cuvette 1 1 Connecting lead Power supply Beaker glass The cuvette is filled with water The water may be colored using fluorescein sodium The transition from water to air is observed The angle of incidence is smaller than the critical angle for water Thus, partial reflection (ray a) and refraction from the perpendicular (ray b) occur | Optics Panel Type  The ray box is turned so that the angle of incidence is greater than the critical angle for water No refraction occurs, merely complete reflection – total reflection The surface of the water acts as a mirror Optics Panel Type | CALCULATING THE INDEX OF REFRACTION (P 33 03) Apparatus: GSN 246 POG 465 POG 461 POG 400.03 KAL 60/5A    Adhesive magnetic board Ray box, 6V 20W Diaphragm and slits Optical disc Connecting lead Power supply Whiteboard marker Ruler 1 The ray box is placed so that the angle of incidence is 30° The angle of refraction is measured along with the distances x and y The experiment is repeated at an angle of incidence 1 = 60° and the corresponding results are noted: x = 7,5 cm x1 = 12,9 cm 1 | Optics Panel Type y = 5,1 cm y1 = 8,8 cm The ratio of the two distances to each other is constant This value is termed the index of refraction n It may be furthermore shown that: sin 30° : sin = sin 60° : sin 1 = 1,47 It is not difficult to deduce from this the Law of Refraction: sin a : sin b = n Using the equation : sin = n the critical angle is found to be about = 43°, which matches up quite well with the results of the experiment Optics Panel Type | TOTAL REFLECTION IN GLASS (P 33 04) Apparatus: GSN 246 POG 465 POG 461 POG 400.03 POG 251 KAL 60/5A      Adhesive magnetic board Ray box, 6V 20W Diaphragm and slits Optical disc Semicircle, lens model Connecting lead Power supply Whiteboard marker Ruler Setup the ray box and the semicircle lens model on the optical disk as shown The light ray emitted by the ray box is to be aimed directly at the center of the lens This may be checked by means of the reflected ray The angle of incidence measured must correspond exactly to the angle of reflection measured The light ray hits the lens at an angle of incidence of 0at first This light ray corresponds to the perpendicular which is drawn in Then the angle of incidence is set again to different values: 1 = 10°, 2 = 20° and 3 = 30° The partially reflected rays are observed along with the refracted ones Angl 10° 20 e of 1 1 1 | Optics Panel Type 30 40 43 45° 50° 60° ° incidence  ° ° ° 18 Angl – – – 23 47 75 90 ° ° ° ° refraction  Dispersion - Ray brushes Total reflection spectrum surface = 90° e of ° At an angle of incidence of = 40° and an angle of refraction of about 75°, color dispersion may be clearly seen At an angle of incidence of about = 43° the refracted ray brushes the surface = 90°) Once the critical angle is reached, only the reflected ray remains – total reflection Optics Panel Type | TOTAL REFLECTION IN A SEMI-CIRCLE BODY (P 33 05) Apparatus: GSN 246 POG 465 POG 461 POG 400.03 POG 251 KAL 60/5A Adhesive magnetic board Ray box, 6V 20W Diaphragm and slits Optical disc Semicircle, lens model Connecting lead Power supply 1 1  The ray of light emitted by the ray box hits the acrylic glass object at a right angle Due to total reflection, it then travels along the boundary between the acrylic glass and the air in a semi-circular direction through the object and leaves it at the bottom end (light beam, aperture angle) The aperture angle is determined by the manner in which the thin, slightly divergent light beam enters the object The individual light rays follow slightly different paths through the acrylic glass object  When the light ray is moved farther inside, the path of the light can be seen more clearly The effect caused by total reflection along the surface where the acrylic glass meets the air can now be easily recognized | Optics Panel Type BASIC PRINCIPLE OF A PHOTOCONDUCTOR (P 33 06) Apparatus: GSN 246 POG 465 POG 461 POG 240.03 KAL 60/5A     Adhesive magnetic board Ray box, 6V 20W Diaphragm and slits C shaped lens, Photoconductor model Connecting lead Power supply 1 1 The light ray emitted by the ray box hits the end of the C-shaped lens at a right angle Due to total reflection, the light ray travels along the surface where acrylic glass meets the air The effect caused by total reflection along the surface where acrylic glass meets the air can be easily recognized Light can be transported in a thin glass body for long distances and even along a crooked path in such a manner This is the basic principle of a photoconductor The refraction of the light ray away from the perpendicular can be observed where the light leaves the acrylic glass object Optics Panel Type | PHOTOCONDUCTOR, FLEXIBLE (P 33 07) Apparatus: GSN 246 POG 465 POG 461 POG 245 KAL 60/5A    Adhesive magnetic board Ray box, 6V 20W Diaphragm and slits Fiber optic, model Connecting lead Power supply 1 1 The model photoconductor is attached to the side of the ray box with fan and circular aperture The light from the bulb is conducted along the flexible photoconductor for some distance and even along a crooked path The spherically shaped opening at the end of the photoconductor causes a lens effect resulting in a distinct light cone at the immediate end of the photoconductor With the aid of this photoconductor, light may be conducted into a small box for example 10 | Optics Panel Type THE PLANE PARALLEL PLATE (P 33 08) Apparatus: GSN 246 POG 465 POG 461 POG 311 KAL 60/5A Adhesive magnetic board Ray box, 6V 20W Diaphragm and slits Prism, trapezoid Connecting lead Power supply 1 1 Whiteboard marker Ruler Optics Panel Type | 11  The light ray enters the surface of the trapezoid at a right angle, passes through the acrylic glass and leaves it without being refracted This ray path is drawn in  The trapezoid object serving as a plane parallel plate is brought into the second position as shown The following phenomena may be observed:  Reflection (light ray 1) and refraction toward the perpendicular occur where air and acrylic glass meet  Refraction from the perpendicular occurs where acrylic glass meets the air The light ray leaving the plane parallel plate is displaced yet parallel to the ray entering Part of the light is reflected at point  This reflected light ray is refracted from the perpendicular where the acrylic glass meets the air (light ray 2) The two light rays travel parallel to each other The greater the inclination of the plane parallel plate, the greater the angle of incidence The greater the angle of incidence, the greater the parallel displacement of the light ray which is refracted twice REFRACTION OF LIGHT IN A PRISM (P 33 09) Apparatus: GSN 246 POG 465 POG 461 POG 310.03 Adhesive magnetic board Ray box, 6V 20W Diaphragm and slits Prism, right angle 1 1 Connecting lead 12 | Optics Panel Type KAL 60/5A Power supply Whiteboard marker Ruler  The prism with a right angle and equal sides is positioned as shown in the diagram At first refraction and partial reflection at the refracting surfaces can be observed  The place where the light ray hits the surfaces is marked, and the outline of the prism and the position of the two perpendiculars are drawn in This shows more distinctly the refraction toward the perpendicular where the ray passes from an optically less to an optically more dense medium and the refraction from the perpendicular in the opposite case  The prism is then turned in a clockwise direction The partially reflected rays become brighter and the refracted ray turns downward; deviation as a whole increases The critical case is reached when the ray brushes the surface DEVIATING PRISM (P 33 10) Apparatus: GSN 246 POG 465 Adhesive magnetic board Ray box, 6V 20W 1 Optics Panel Type | 13 POG 462 POG 310.03 POG 220.01 POG 220.02 KAL 60/5A Diaphragm and slits Prism, right angle Color filter red Color filter blue Connecting lead Power supply 1 1  The prism with a right angle and equal sides is positioned about 20 cm from the ray box so that one of the shorter sides is perpendicular to the light rays reaching it  The hypotenuse of the prism (boundary surface between acrylic glass and air) acts a plane mirror due to total reflection The approaching light rays change direction by a total of 90° INVERTING PRISM (P 33 11) 14 | Optics Panel Type Apparatus: GSN 246 POG 465 POG 462 POG 310.03 POG 220.01 POG 220.02 KAL 60/5A Adhesive magnetic board Ray box, 6V 20W Diaphragm and slits Prism, right angle Color filter red Color filter blue Connecting lead Power supply 1 1 1  The prism with a right angle and equal sides is positioned about 20 cm from the ray box so that its hypotenuse is perpendicular to the light rays hitting it The three parallel light rays enter the prism in its top half  Being totally reflected twice from the shorter sides of the right-angled prism with equal sides, the rays leaving it so parallel to the ones entering it, yet in the opposite direction In addition, because the three rays are totally reflected twice, their order is reversed upon leaving The two short sides of the prism act as two plane mirrors situated at right angles to each other Note: An image may be entirely reversed (i.e up < > down, left < > right) by using two prisms placed back to back and including a right angle between them Optics Panel Type | 15 TORRICELLI'S PRISM Apparatus: GSN 246 POG 465 POG 462 POG 310.03 POG 220.01 POG 220.02 KAL 60/5A   Adhesive magnetic board Ray box, 6V 20W Diaphragm and slits Prism, right angle Color filter red Color filter blue Connecting lead Power supply 1 1 1 The prism is positioned so that the light ray entering it and its hypotenuse are parallel to each other During the transition from air to acrylic glass, the light ray entering is partially reflected and partially refracted toward the perpendicular The entering and the reflected ray are at right angles to each other The refracted light ray is totally reflected by the hypotenuse and then refracted from the perpendicular by the short end on the other side as the ray passes from acrylic glass to air The light ray entering and the one leaving are parallel to each other but displaced Note: Torricelli's Prism is used to reverse images when the course of the light rays is to remain unchanged and the top is merely to be exchanged with the bottom 16 | Optics Panel Type