13) Which type of joint is used to run the wires from horizontal position to the vertical position either down wards (or) upwards in T.W batten wiring?

14) What is the length of over lapping is to be provided for jointing 25 mm width batten in straight joint of T.W. batten?

15) Which type of joint is used to extent the length of T.W batten?

16) Which conduit fitting is used to join additional conduit pipe in long run of conduit wiring?

17) Which type of wiring require less number of bends can be taken through shortcut route in the roof?