Expert please answer this question for me that is in the image

Expert please answer this question for me that is in the image a] Using the ring system, draw a circuit diagram for lightning In a room having a bulb, a socket•and a fan. What are advantages of ring system? [31 Find the effective resistance between the points A•and H A and D in the following circuit. c -rc«ide diagram A, B, CÄare fo rauIUms suspended from the are equal to each other while same elastic string PQ. The ngth an erth that of D. the length of pendulum is s ons. Pendulum A is set int a mo VI ra ns taking place in pendulums B and D? Name the*pe