'l. A group of students investigated the relationship between the number of turns in the secondary coil of a transformer and its voltage. First, they placed a primary coil around one end of an iron core and a secondary coil with 300 turns around the other. Next, they set the voltage in the primary coil (V9) to 14 V and measured the resulting voltage in the secondary coil (V5). Finally, they repeated the process three more times, using secondary coils with 600, 900 and 1200 turns and measuring the voltages in the secondary coil a) State a suitable hypothesis for the student's investigation b) State one variable held constant in the students investigation 0) The student conducted these tests three times and calculated an average voltage for each secondary coil. The data are shown in the table below Voltage In the secondary coi|(V Number of turns in the secondary coil Trial 1 Trial 2 Trial 3 Average 300 12 32 12. 83 1283 12-33 \" 25.55 25.25 25.55 25.55 m 55.55 55.55 38-85 38-83 1200 51.54 51.54 51.6? 51-55 i) State why three voltage measurements were taken for each secondary coil ii) Compare the precision of the set of results for the secondary coil with 600 turns with the precision for the secondary coil with 900 turns d) The average secondary voltage (V) was plotted against the number of turns in the secondary coil The gradient of the line best t was 0.043 i) Use the gradient of the line of ebay fit to determine the number of turns in the primary coil ii) The primary coil had 300 turns State the evidence there is a systematic error in the experiment