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 IQ scale is open-ended. Your IQ is 100 times your mental age divided by your actual age. Mental age is the age at which your IQ test results would be average. So let's say you're 10 years old, but your IQ test results are those of an average 12 year old. Your IQ would be 100 x 12 / 10, or 120. If you are 10 years old and your IQ is 80, your IQ test results are average for an 8 year old. If your IQ is 100, you're right in the middle of other people your age. It's very important to realize that your IQ is only a comparison of test scores.