2021 AHS Physics Prelim Paper 3

1 6 Sep 2021 1 hour 50 minutes Anglican High School Secondary Four Preliminary Examination 2021 CLASS CLASS INDEX 4 Anglican High School 2021_S4_Prelim_PHY_P3 S4 ___________________________________________________________________________________ This document consists of 11 printed pages.

2 1 In this experiment, you will investigate the resistivity and the power dissipated in a length of resistance wire. You are provided with:  a length of resistance wire (W) attached to a meter rule,  a sample of resistance wire  a micrometer screw gauge  an ammeter (0 – 1 A),  a voltmeter (0 – 5 V),  a switch,  a power supply,  a fixed resistor (R2),  connecting wires,  a jockey. Set up the apparatus as shown in Fig. 1.1 (a) Measure and record d, the diameter of the sample of resistance wire. d = …………………..…… [1] (b) Calculate the cross-sectional area of the resistance wire, in m2, using the equation shown. A =  𝑑2 4 A = …………………… m2 [1] Fig. 1.1 +  jockey Anglican High School 2021_S4_Prelim_PHY_P3 [Turn over 0 cm metre rule resistance wire, W fixed resistor, R2 power supply  𝑙

3 (c) Close the switch. Place the jockey on the resistance wire so that a length 𝑙 of 0.8 m of resistance wire is connected in the circuit. Record the current I in the circuit and the potential difference V across the length of wire. I = …………………………….. V = …………………………….. [2] (d) Open the switch. (i) Calculate the resistance R of 0.8 m of the wire using the equation shown. 𝑅 = 𝑉 𝐼 R = ………………………… [1] (ii) The resistance R and the resistivity  are related by the equation 𝑅 = 𝑙 𝐴 where A is the cross-sectional area and 𝑙 is the length of the wire. Calculate the resistivity of the wire, .  = ………………………… [2] (iii) Calculate the power dissipated P in 0.8 m of the wire using the equation shown. P = I V P = ………………………… [1] (e) Repeat (c) for 𝑙 = 0.4 m. Hence determine P for 𝑙 = 0.4 m. P = ………………………… [1] (f) Using your answers to (d)(iii) and (e), explain whether the power dissipated P is directly proportional to the length 𝑙 of the wire. …………………………………………………………………………………………………………. …………………………………………………………………………………………………………. …………………………………………………………………………………………………..…. [1] [Total: 10] Anglican High School 2021_S4_Prelim_PHY_P3 [Turn over

4 2 In this experiment, you will investigate a spinning mass. You are provided with:  a 1 N mass-hanger and four 1 N weights,  a half-metre rule,  a length of string attached to a wooden rod,  a stopwatch,  a stand, boss and clamp. Set up the apparatus as shown in Fig. 2.1 Ensure that the weight is directly above the base of the stand so that it does not topple over. Adjust the position of the boss so that the bottom of the 5 N weight is approximately 2 cm above the base of the stand. Fig. 2.1 shows the weight and the strong in the equilibrium position. (a) Measure the height h of the top of the weight above the base of the stand in the equilibrium position, h = …………………………….. The length of j of one side of the string, j = …………………………….. the distance k between the two points where the string is attached to the rod. k = ……………………………. [1] Fig. 2.1 Anglican High School 2021_S4_Prelim_PHY_P3 [Turn over

5 (b) Rotate the weight clockwise when viewed from above until h increases by 10 mm. Release the weight and immediately start the stopwatch. The time for the string to first unwind is t. Determine an accurate value for t. t = …………………………… [2] (c) The rate at which gravitational potential energy is transferred by the spinning weight can be calculate using the equation 𝑃 = 𝑊ℎ 𝑡 Where W is the weight on the string and h is the change in h. Calculate P1 using your value of t from (b). P1 = …….…………………….. [2] (d) Remove three weights from the mass-hanger. Repeat (b) and (c) to obtain a new value, P2. P2 = …….…………………….. [1] (e) Plan an experiment to investigate the relationship between P and W. Your plan should include  a list of the quantities that remain constant,  a description of how you would perform the experiment  a sketch of the graph that you would plot using preliminary observations. Anglican High School 2021_S4_Prelim_PHY_P3 [Turn over

6 …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. …………………………………………………………………………………………………………….. ……………………………………………………………………………………………………….… [4] [Total: 10] Anglican High School 2021_S4_Prelim_PHY_P3 [Turn over

7 3 In this experiment, you will apply several forces to a metre rule. You are provided with:  seven slotted masses,  a spring with a string loop attached,  two metre rules (one of them with a rubber band wrapped around its centre)  a pair of vernier calipers,  a set square  a stand, boss and clamp. (a) Measure and record the length lo of the unstretched spring, as shown in Fig. 3.1. lo = ……………………….. [1] (b) Record the distance L from one end of the metre rule to the rubber band, as shown in Fig. 3.2. Do not adjust the position of the rubber band throughout the experiment. L = ……………………….. [1] (c) Measure and record the diameter d of one of the slotted masses, as shown Fig. 3.3. d = ……………………….. [1] Fig. 3.1 Fig. 3.2 Fig. 3.3 Anglican High School 2021_S4_Prelim_PHY_P3 [Turn over

8 (d) (i) Set up the apparatus as shown in Fig. 3.4. One of the slotted masses should be placed on the metre rule and be resting against the rubber band. (ii) Adjust the clamp so that the bottom edge of the raised end of the metre rule is 25.0 cm above the bench and the spring is vertical. Measure and record the length l of the stretched spring. l = ……………………….. [1] (iii) Calculate e where e = l - lo. e = ……………………….. [1] (e) Place a second mass next to t