2022 CHIJ Phy Prelims P3

CONVENT OF THE HOLY INFANT JESUS SECONDARY Preliminary Examination in preparation for the General Certificate of Education Ordinary Level 2022 CANDIDATE NAME CLASS REGISTER NUMBER PHYSICS Paper 3 Practical Candidates answer on the Question Paper. 6091/03 12 September 2022 1 hour 50 minutes READ THESE INSTRUCTIONS FIRST Write your class, register number and name in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions. All of your answers should be written in this Question Paper: scrap paper must not be used. Graph paper is provided in this Question Paper. Additional sheets of graph paper should be used only if it is necessary to do so. You will be allowed to work with the apparatus for a maximum of 55 minutes for each section. You are expected to record all your observations as soon as they are made. An account of the method of carrying out the experiments is not required. The use of an approved scientific calculator is expected, where appropriate. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. Shift Laboratory For Examiner’s Use 1 2 3 Total This document consists of 12 printed pages. [Turn over

2 CHIJSec/2022/OLevelPrelim/6091/03 Section A 1 In this experiment, you will investigate the effect of a frictional load on an electric motor. You have been provided with: • A 4.5 V power supply, • a small electric motor, • an ammeter, • a voltmeter, • a resistor of resistance 10 Ω, • a switch or plug key, • electrical leads, • a wooden rod, • a piece of Blu-Tack. (a) Set up the circuit shown in Fig. 1.1. Fig. 1.1 Fix the motor to the bench using the piece of Blu-Tack, as shown in Fig. 1.2. Fig. 1.2 (i) With the switch open, record the voltmeter reading V0. V0 = ……………………………..[1] (ii) Check that the shaft of the motor is free to spin by rotating it a few times by hand. Close the switch. Record the potential difference V1 across the motor and the current I1 in the circuit. V1 = ……………………………….. I 1 = ……………………………..[2] 4.5 V 10 Ω motor motor shaft of motor bench Blu-Tack

3 CHIJSec/2022/OLevelPrelim/6091/03 (iii) Open the switch. Calculate the input power P1 to the motor using the equation shown. P1 = V1 I1 P1 = ……………………………..[1] (b) Close the switch. Use the wooden rod to press gently on the shaft of the motor, as shown in Fig. 1.3. Fig. 1.3 Press down on the wooden rod until the shaft just stops spinning. (i) Record the potential difference V2 across the motor and the current I2 when the motor is not spinning. V2 = ……………………………….. I 2 = ……………………………..[1] (ii) Open the switch. Calculate the resistance R of the motor using the equation shown. = 2 2 VR I R = ……………………………..[1] [Turn over shaft of motor motor bench wooden rod press down

4 CHIJSec/2022/OLevelPrelim/6091/03 (c) Some of the input energy to the motor in (a)(iii) is wasted as thermal energy in the coil of the motor. The proportion Q of the energy wasted in this way is given by the equation shown. = 1 1 RQ V I Calculate Q. Q = ……………………………..[1] (d) A student uses the apparatus shown in Fig. 1.4 to determine the minimum force F that the rod exerts on the shaft of the motor to stop it spinning. Fig. 1.4 Describe how F may be determined using the apparatus in Fig. 1.4. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. …………………………………………………………………………………………… [2] (e) Suggest a change to the apparatus in Fig. 1.4 so that F can be measured directly. ……………………………………………………………………………………………….. ……………………………………………………………………………………………. [1] [Total: 10] motor Blu-Tack bench boss stand rod spring wooden rod string slotted masses

5 CHIJSec/2022/OLevelPrelim/6091/03 2 In this experiment, you will investigate the speed of a glass ball rolling down an inclined track. You have been provided with • a support, • two metre rules, • a glass ball, • a stopwatch, • Blu-Tack, • a 30 cm ruler, • a piece of cloth to act as a stop. Set up the apparatus, as shown in Fig. 2.1. Fig. 2.1 Place the support on the bench with the side marked ‘Top’ facing upwards. Place the two metre rules on the support. Use a small piece of Blu -Tack for each metre rule to prevent them from moving on the support. The metre rules should be placed on the support at the 3 cm marks and 5 mm apart. Ensure that the gap between the metre rules is 5 mm along the length of the metre rules. Fix the metre rules to the bench at the 100 cm ends with Blu-Tack. (a) Measure the height h of the lower surface of the metre rules above the bench at the 0 cm mark, as shown in Fig. 2.2. Fig. 2.2 h = ………………………………. [Turn over 3 cm mark 3 cm mark metre rule metre rule 100 cm Blu-Tack Blu-Tack Blu-Tack Blu-Tack support stop 0 cm mark bench h 100 cm mark stop

6 CHIJSec/2022/OLevelPrelim/6091/03 (b) Place the centre of the glass ball at the 1 cm mark on the metre rules. Release the ball and immediately start the stopwatch. The time taken for the ball to reach the end of the track is 0t . Determine an accurate value for 0t . 0t = ……………………………[2] (c) The average speed of the ball is calculated using the formula shown. =average speed time taken distance travelled In (b) the ball travels 99.0 cm. Calculate the average speed 0v of the ball for this distance. 0v = ……………………………[1] (d) Replace the ball at the 1 cm mark. Reset the stopwatch to zero. Release the ball and start the stopwatch. Stop the stopwatch when the ball reaches the 51.0 cm mark on the track. The reading on the stopwatch is 1t . Record your value for 1t . Calculate the average speed 1v of the ball for this distance. 1t = ……………………………… 1v = ……………………………[1] (e) It is suggested that 0v should be equal to 1v . Explain whether your values of 0v and 1v support this suggestion. ……………………………………………………………………………………………….. …………………………………………………………………………………………… [1]

7 CHIJSec/2022/OLevelPrelim/6091/03 (f) Plan an experiment to investigate the relationship between average speed and height h. Your plan should include • the quantities that you should keep constant, • a detailed description of how you would perform the experiment, • a suitable table in which to display your measurements and calculated values (you do not need to enter any data into the table), • a statement of the graph that you would plot to test the relationship, ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ...………………………………………………………………………………………[5] [Turn over [Tot