SmartScreen Sample questions A answers Electrical Installations (Buildings and Structures) : 36) ' where a . 23. Which one of the following is the conduit capacity factor to be used 25mm conduit has 2 bend in a 6m run? a) 111 b) 182 333 d) 600 is ee 24. The electrical system in which the connection to earth is by an earth electrode Is: lal ) TN-S c) TN-C d) TIN-GeS 25. Which one of the following earthing + suppl | installation (L4.1) arrangements is shown in the diagram? a) TN-C-S b) TT Cc) TN-C d) TN-S 26. Which one of the following is the correct name of the component which links the (L4.2) main earthing terminal of an installation to the means of earthing? a) Main protective bonding conductor b) Supplementary equipotential bond Cc) Earthing conductor d) Functional earth 27. What is represented by Z, in the following formula: (L4.2) Zs=Zet(RitR2)? a) Total earth fault loop impedance b) External earth fault loop impedance Cc) Final circuit earth fault loop impedance d) Combined resistance of the earth path 28. | Which one of the following defines the term 'main protective bonding conductor ? (L4.2) a) The conductor which links the MET to an earth electrode b) The conductor which links the MET to extraneous conductive parts Cc) The conductor which links the MET to exposed conductive parts d) The conductor which links the MET to the means of earthing 29. Which one of the following is the purpose of the main protective bonding (L4.2) conductor? a) To raise extraneous conductive parts to the same voltage as the supply under overload b) To raise extraneous conductive parts to the same voltage as the supply under earth fault conditions Cc) To raise extraneous conductive parts to the same voltage as the supply under normal conditions d) To raise extraneous conductive parts to the same voltage as the supply under transient fault conditions 30. | Which one of the following is an exposed conductive part? (L4.3) a) Metal-clad switch b) Structural steelwork Cc) Air conditioning ducting d) Metallic oil service pipe Page 4 of 6 2025 City and Guilds of London Institute. All rights reserved. www.SmartScreen.co.uk