State the four methods of laying of cable. State precautions while laying of underground cable in the situation : (i) Minimum clearance between cable and water pipe line when running in parallel. (ii) Minimum clearance between cable and water pipe line when running in parallel. (iii) If cable is laid through pipe what should be diameter of pipe. (iv) When more than one cable is to be laid in the same trench, what should be minimum spacing between two cables ?