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.
How an IQ Test is Scored. The term IQ actually stands for intelligence quotient. To determine a person's IQ, a person's mental age is multiplied by 100 and then divided by the chronological age. The average IQ is said to be 100, so anything above that is considered above average. The range of what is considered developmentally disabled is thought to be anything below 70. Most people who are considered geniuses have IQs above 145. What an IQ Test Does Not Measure.