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.
IQ stands for Intelligence Quotient. It is your mental age divided by you chronological age. The average IQ is 100, and most people are within 15 points from that. If you scor â¦ e above 115 you are considered very smart, and if you score above a 130, you are considered a genius. if you score below an 85, you are considered dumb, and if you score below a 70, you are considered mentally retarded.