The Critical Angle Derivation. So the critical angle is defined as the angle of incidence that provides an angle of refraction of 90-degrees. Make particular note that the critical angle is an angle of incidence value. For the water-air boundary, the critical angle is 48.6-degrees.
The average IQ is 100. Have you wondered what your IQ score is? Our original IQ Test will give you a fast, free and accurate iq score. Take our quick free IQ test and find out just how smart you are. What others had to say... A person's Intelligence Quotient (IQ) is, arguably, one of their most important characteristics.
Historically, IQ is a score obtained by dividing a personâs mental age score, obtained by administering an intelligence test, by the personâs chronological age, both expressed in terms of years and months. The resulting fraction is multiplied by 100 to obtain the IQ score. When current IQ tests are developed, the median raw score of the norming sample is defined as IQ 100 and scores each standard deviation (SD) up or down are defined as 15 IQ points greater or less, although this was not always so historically.