2022 NCHS Phy Prelims P3

1 Name: Register Number: Class: NAN CHIAU HIGH SCHOOL PRELIMINARY EXAMINATION 2022 SECONDARY FOUR EXPRESS PHYSICS 6091/03 Paper 3 Practical Students answer on the Question Paper. 5 Aug 2022, Friday 1 hour 50 minutes READ THESE INSTRUCTIONS FIRST Write your name, register number and class on all the work you hand in. Circle the practical shift and laboratory where appropriate, in the boxes. Write your answers in the spaces provided on the Question Paper. For the two questions in Section A and one question in Section B, you will be allowed to work with the apparatus for a maximum of 55 minutes before handover. You are expected to record all your observations as soon as these observations are made. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate decimal places, significant figures or units for numerical answers. The number of marks is given in brackets [ ] at the end of each question or part question. Take g to be 10 N/kg. This paper consists of 10 printed pages including the cover page. For Examiner’s Use 1 /10 2 /10 3 /20 Total /40

2 1 You are to determine the specific heat capacity of oil. You are provided with • a thermometer, • a resistance heater • a d.c. power supply, • an ammeter, • a voltmeter, • a switch, • a beaker with oil, • a stopwatch. (a) On Fig. 1.1, complete the circuit diagram to connect the heater correctly to the power supply, the ammeter and the voltmeter. [2] Fig. 1.1 (b) Initially the oil is at room temperature. Record the room temperature θi. θi = ................... (c) Close the switch of the circuit and start the stopwatch at the same instant. Record the current, I and the potential difference of heater, V. [2] I = ................... V = .................. (d) Open the switch after 5 minutes. Record the highest temperature reached after the switch is opened. θf = ................... oil thermometer heater d.c. power supply

3 (e) Calculate the electrical energy E used to heat up the oil. [2] E = .................. (f) The specific heat capacity c of the oil is given by c = IVt/mΔθ where t is the time taken when the heater is switched on, m is 0.035 kg. Calculate the specific heat capacity c of the oil. Give the appropriate unit. c = ......................... [2] (g) The value of c calculated is different from its true value. Suggest two reasons why this is so. [2] 1................................................................................................................................. ................................................................................................................................... ................................................................................................................................... .......................................................................................................................