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.
The term IQ, or Intelligence Quotient, generally describes a score on a test that rates the subject's cognitive ability as compared to the general population. IQ tests use a standardized scale with 100 as the median score. On most tests, a score between 90 and 110, or the median plus or minus 10, indicates average intelligence. A score above 130 indicates exceptional intelligence and a score below 70 may indicate mental retardation.