State three types of inductive transformer(3 marks)

Explain why pumped storage electricity generation is used, in preference to traditional fuel sources, to provide supply flexibility when demand fluctuates.(3 marks)

A single-phase electric motor has a rating of 2.55 kW and the current lags the voltage by 32°. Calculate the apparent power and reactive power for this motor.(5 marks)

Explain why all Live conductors of the same A.C. circuit must enter a steel-cased consumer unit through one single hole.(4 marks)

State three gases or metallic vapors commonly used in discharge lamps.(3 marks)

Explain why star-delta motor control equipment is used in preference to direct-on-line(3 marks)

Explain the drawbacks of BS 3036 fuses.(6 marks)

State three factors, given in BS 7671, to be taken into account when calculating the maximum demand of an installation.(3 marks

A new passive infra-red occupancy sensor has been installed to control the lighting in a hotel corridor. Describe the process of carrying out functional testing of these sensors.(3 marks)

Describe three practical measures that can be taken to ensure the safety of other people, when carrying out inspection and testing.(3 marks)

Explain why a newly installed gas central heating boiler must be disconnected from a circuit before an insulation resistance test can be carried out.(3 marks)

State three hazardous materials that may require specialist disposal when undertaking fault rectification work.(3 marks)

Identify three pieces of verbal information an electrician should seek from a user when undertaking diagnosis of an intermittent electrical fault.(3 marks)

State the upper voltage limits for Extra-Low Voltage.(2 marks)

Explain the effect of running a cable through 200 mm of thermal insulation.(3 marks)

Explain why Low Voltage circuits with surge protective devices may have the insulation resistance test voltage reduced.(4 marks)

State three special installations or locations other than those divided into zones.(3 marks)

A new circuit is to be installed to an existing electrical installation within a motor vehicle repair workshop. The repair workshop undertakes a range of mechanical and body repairs to vehicles and the ambient temperature can be 35 °C during certain processes. The supply and installation form a 400 V, three-phase, TN-C-S system. The DNO has quoted the Ze to be 0.35 Ω. The new circuit is to supply a 7.4 kW three-phase paint-baking oven heater, 30 m from the origin of the installation, but must be contained in existing, galvanised trunking for 3 m of the run. Within this existing trunking are three other circuits. The circuit is to be wired in 70 °C thermoplastic single-core cable and protected by a type C circuit breakerto BS EN 60898. Determine a suitable cost-effective installation design that complies with BS 7671.(15 marks)