Q. two wires a and b of circular cross section are made of the same metal and have equal lengths, but the resistance of wire a is three times greater than that of wire b. what is the ratio of their cross-sectional areas? how do their radii compare?
Q. You hold a spherical salad bowl 90 cm in front of your face with the bottom of the bowl facing you. The salad bowl is made of polished metal with a 35cm radius of curvature. What is the image (your face's image) distance along the central axis from the salad bowl?