https://www.pearson.com/channels/physics/exam-prep/asset/302c66b4/a-biconcave-lens-is-made-from-fused-quartz-as-shown-below-compute-the-focal-leng
A biconcave lens is made from fused quartz (refractive index 1.46) is shown below. Compute the focal length of this lens.
biconcave lensfused quartzrefractive indexmade