TJC 2026 H2 Prelim P4

TEMASEK JUNIOR COLLEGE 2026 JC2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CENTRE NUMBER S INDEX NUMBER Physics 9478/04 Paper 4 Practical 01 September 2026 2 hours 30 min 1 In this experiment, you will investigate the motion of a system of masses. This booklet consists of 14 printed pages

2 1 (a) Set up the apparatus as shown in Fig. 1.1. Fig. 1.1 The distance between the bottom of the split cork and the top of the upper string loop is x. Adjust the apparatus until x is approximately 15 cm. Measure and record x. x = ........................................ Move the bottom mass a short distance to the left and release it. The masses will oscillate with a period T. Determine and record T. T = ........................................ [2]

3 (b) Vary x and repeat (a). Present your results clearly. [4] (c) T and x are related by the expression: 4T Px Q=+ where P and Q are constants. Plot a suitable graph using a spreadsheet to determine P and Q. Sketch the graph in the space below. Write down the equation of the trendline. P = ........................................ Q = ........................................ [4] [Total : 10]

4 2 In this experiment, you will investigate stretched rubber bands. (a) Set up the apparatus as shown in Fig. 2.1. Clamp the hacksaw blade with its teeth facing upwards. Place the rubber bands on the blade so that the tops of the rubber bands are approximately 8 cm apart. You may wish to use some of the Blu-Tack to secure the tops of the rubber bands on the blade. Suspend mass m from the rubber bands, where m = 300 g. Record m. m = .......................................

5 The angle between one of the rubber bands and the hacksaw blade is 𝛼, as shown in Fig. 2.1. The length of one of the stretched rubber bands is 𝑏. Measure and record 𝛼 and 𝑏. 𝛼 = ....................................... b = ....................................... [2] (b) Change m to 200 g. Adjust the position of the tops of the rubber bands on the blade so that 𝑏 has the same value as in (a). Record m. m = ....................................... Measure and record 𝛼. 𝛼 = ........................................ [1] (c) It is suggested that: sin 𝛼 = 𝐶𝑚 where 𝐶 is a constant. Use your values from (a) and (b) to determine two values of 𝐶. first value of C = ........................................ second value of C = ........................................ [1]

6 (d) It is suggested that: 𝐶 = 𝑔2𝑒𝑘 where 𝑒 is the extension of the rubber band with extended length 𝑏, 𝑘 is the force constant of this rubber band and the acceleration of free fall 𝑔 = 9.81 m s−2. Determine a value for 𝑘. Show your working. k = ........................................ [3] (e) Suggest one significant source of error and a possible improvement to reduce this error in this experiment. Error: [1] Improvement: [1]

7 (f) A student investigated the discharge of a capacitor through a resistor. The current 𝐼 in the circuit is related to time 𝑡 by 𝐼 = 𝐼0𝑒−𝑡/𝜏 where 𝐼0is the initial current and 𝜏 is the time constant of the circuit. The capacitor has capacitance 𝐶 = 2200 𝜇F and is initially charged to 𝑉0 = 6.0 V. The current was recorded using a data logger and the data are provided in the digital file capacitorDischarge.csv. (i) Plot a suitable graph using a spreadsheet to determine the time constant , 𝜏, of the circuit. Sketch the graph in the space below. Write down the equation of the trendline. 𝜏 = ........................................ [2] (ii) Use a spreadsheet to estimate the charge Q that flows through the circuit during discharging, for the data given in capacitorDischarge.csv. Q = ........................................ [1] (iii) Explain how the value of Q was obtained from the spreadsheet data. [1] (iv) Determine whether the charge calculated in (iii) is equal to the initial charge stored on the capacitor. Explain your answer. [2] [Total : 15]

8 3 This experiment investigates the properties of a coil of wire. (a) You have been provided with two cardboard tubes with wire wrapped around them. The diameter of the tube labelled Y is DY, as shown in Fig 3.1. The diameter of the wire is dY. Fig. 3.1 Measure and record DY and dy. Dy = cm dy = mm [2]

9 (b) (i) The total length of the wire is LY. Estimate and record your value for LY. Show your working. Ly = cm [2] (ii) Estimate the percentage uncertainty in your value of Ly . percentage uncertainty = [1] (c) Connect the circuit shown in Fig. 3.2 where resistor R has a resistance R of 15 Ω. Fig. 3.2 Close the switch. Note and record R and the ammeter reading I. R =  I = A [1]

10 Open the switch. (d) Vary R and repeat (c). Present your results clearly. [3] (e) I and R are related by the expression: IR = GR +H where G and H are constants. The resistance XY of coil Y is given by: =Y HX G . Plot a suitable graph using a spreadsheet to determine value of XY. Sketch the graph in the space below and write down the equation of the trendline. XY =  [3]