Compute the speed of light in a fiber optical fiber. v = d / t. D = 15 cm, t = .2 micro sec, .5 v /div and D = 20 m, t = .2 micro sec, .8 v / div. Approximate the error in v (employ 1% for the uncertainty in the length of the fibers). By using the accepted value of the speed of light, find out the index of refraction of the fibers? Determine the critical angle for the fiber? Approximate the energy loss in the longer cable by employing the reduction in signal amplitude one fiber was 15 cm, and the fiber was 20 m.