...called the angle of incidence. The angle ft which .Va forms with / is called the angle of refraction. The sine of the angle of incidence divided by the sine of the angle of refraction is, for any given pair of media, constant, and is called the index of refraction. When the index of...

...reflection, and refraction respectively. The angle of reflection is equal to the angle of incidence. The sine of the angle of incidence divided by the sine of the angle of refraction is a constant, independent of the angle of incidence, and of the pitch of the sound. All these angles...

...refracted portion of the ray with the normal bh, is the angle of refraction, and the sine of this angle is equal to the sine of the angle of incidence divided by the relative refractive index from air into glass ; or, to put the relationship of the angles in another...

...formed by the ray with the perpendicular after refraction is called the angle of refraction — angle R. The sine of the angle of incidence, divided by the sine of the angle of refraction, gives the index of refraction. Glass used in the manufacture of spectacles has an index of refraction...

...refraction is somewhat as follows : the index of refraction of a substance is equal to the quotient of the sine of the angle of incidence divided by the sine of the angle of refraction. A simple figure will readily make this clear. Let ABCD (figure i) represent the outline of a circular...

...refracting medium to the passage of light. In other words the index of refraction of a substance is the sine of the angle of incidence divided by the sine of the angle of refraction. The law is illustrated in the following way : Let M be a refracting medium ; abc a train of plane waves...

...sin r, whence ac ac b_c smi = ac = be Therefore [cf tion (18)] n= £EJ (19) sin r ad ad sin r ac Thus the index of refraction is -equal to the sine of the...incidence divided by the sine of the angle of refraction. Since these angles are easily measured, this ratio is more convenient to use than that of the velocities....

...(Fig. 206). The value of the critical angle may be found as follows: The index of refraction equals the sine of the angle of incidence divided by the sine of the angle of refraction, equals, in this case, the sine of the critical angle divided by the sine of 90° (which is unity)....

...the rarer medium and that taken by the ray in the denser medium. The relationship is expressed thus : Sine of the angle of incidence divided by the sine of the angle of refraction equals the indexofrefraction. In the figures, Sin CBN' of refraction. Worked out completelv in Fig....

...in this equation, we have Z i = 1.D + £ A, or » = K-*> + .4)- (2) Since the index of refraction = sine of the angle of incidence divided by the sine of the angle of refraction, . sin . • Index ot retraction = sin ^ A The sines of these angles can be found in Table 13, Appendix,...