EWRB Exams Practice Questions and Correct Answers

A new flexible chord has been fitted, which of the following insolation resistance test values would be correct? A. 10 MOhm B. 0.5 Ohm C. 0.5 MOhm D. 1. Ohm A. 10 MOhm Question 2: The maximum current a flexible cord can carry safely without overheating depends mainly on: A. The type of supply, a.c. or d.c. B. The cross-sectional area of the flexible cord conductors. C. The colours of the flexible cord conductors. D. The number of cores in the flexible cord. B. The cross-sectional area of the flexible cord conductors. Question 3: A 230V heater comprises two elements connected in series across the supply. If one resistance becomes open-circuited, what is the voltage across the other resistance? A. 0V B. 400v C. 690v D. 230v A. 0V Question 4: The symbol of a square within a square on a name-plate of an electrical appliance is used to indicate that the appliance is double-insulated. Which one of the following terms on an appliance nameplate would also indicate that the appliance is double-insulated. A. Class I B. Class II C. All- insulated D. 240v B. Class II Question 5: A switch controls two heating elements both of the same resistance. The settings that can be selected on the switch are high, medium and low. When the high position is selected on the switch, it will connect: A. Two elements in series with the supply. B. One element in series with a suitable resistance. C. One element only across the supply. D. Two elements in parallel across the supply. D. Two elements in parallel across the supply. Question 6: When fighting a fire in live electrical equipment, which of the following fire extinguishers should not be used? A. Water - gas expelled. B. Dry powder. C. Vaporising liquid. D. Carbon dioxide. A. Water - gas expelled Question 7: State the reason why a bayonet cap adaptor must not be used to supply a Class I electrical appliance. A. Wrong voltage rating. B. No earthing facility. C. Not mechanically strong enough. D. The cord supplying the adaptor is the wrong shape. B. No earthing facility. Question 8: Which one of the following changes would reverse the direction of rotation of a single-phase capacitor-start motor? A. Reverse the phase and neutral supply conductor connections at the motor terminal block. B. Reverse the connections of the centrifugal switch. C. Reverse the connections of the run winding. D. Reverse the connections of the capacitor. C. Reverse the connections of the run winding.