AQA A Level PHYSICS (7408/3A) Paper 3 Section A Question Paper & Mark scheme (Merged) June 2023 [VERIFIED]

AQA A Level PHYSICS (7408/3A) Paper 3 Section A Question Paper & Mark scheme (Merged) June 2023 [VERIFIED] A stroboscope emits bright flashes of white light. The duration of each flash and the frequency of the flashes can be varied. Table 1 shows information about the stroboscope. Table 1 Minimum Maximum Duration of each flash / μs 60 300 Frequency of flashes / Hz 1 150 The duration of each flash is T1. The time from the start of a flash to the start of the next flash is T2. The duty cycle of a stroboscope is defined as T1 . T2 0 1 . 1 What is the maximum duty cycle of the stroboscope? Tick () one box. [1 mark] 6.0 × 10−5 3.0 × 10−4 90×10−3 Do not write outside the box 3 0 1 . 2 Figure 1 shows images produced in an experiment in which a bouncing ball is illuminated by a stroboscope. The stroboscope flashes at a constant frequency. Figure 1 Suggest why T1 must be very short for this experiment. [1 mark] Do not write outside the box 4 Figure 2 shows the first six images starting with n = 0, where n is the image number. Figure 2 The images are used to determine: H, the vertical distance from the bottom of the ball to the floor when n = 0 h, the vertical distance from the bottom of the ball to the floor for each non-zero value of n. The n = N image is produced at the instant that the ball hits the floor for the first time. For n between 0 and N it can be shown that H− h = u 0 n + g n 2 f 2 f where u0 is the vertical velocity of the ball when n = 0 g is the acceleration due to gravity f is the frequency of the flashes. Do not write outside the box 5 In order to find g, a graph is plotted with values of H −h 0 1 . 3 on the y-axis. n Suggest what is plotted on the x-axis. Go on to explain how g is determined from this graph. [3 marks] The following data are recorded. H = 1550 mm f = 31.0 Hz The graphical analysis of data from Figure 1 gives g as 9.79 m s−2 . 0 1 . 4 Determine u0. [3 marks] Do not write outside the box 6 Figure 3 shows positions of the bottom of the ball for n = 40 to n = 66 In this range of positions, the ball makes contact with the floor for the second and third times. Values of h, the vertical distance from the bottom of the ball to the floor, are plotted on the y-axis. Values of s, the horizontal displacement from a point on the floor below the centre of the n = 0 image, are plotted on the x-axis. Figure 3 Do not write outside the box 7 0 1 . 5 Determine, in mm s −1 , the horizontal velocity of the ball between the second and third contacts of the ball with the floor. [2 marks] horizontal velocity = mm s−1 0 1 . 6 Determine the time between the second and third contacts. Annotate Figure 3 to show your method. [3 marks] Do not write outside the box 8 0 2 Figure 4 is a plot of current–voltage data for a filament lamp L. Figure 4 Do not write outside the box 9 The current I was measured as the voltage V across L was increased at a steady rate. These data were obtained using a current sensor and a voltage sensor connected to a data logger. The logger recorded data at a rate of 2.5 Hz. 0 2 . 1 Determine, in V s−1 , the rate of increase of V. [2 marks] rate of increase of V = V s−1 0 2 . 2 State two advantages of using data logging for this experiment. [2 marks] 1 2 Do not write outside the box 10 0 2 . 3 Figure 5 shows two circuits that can be used to collect current–voltage data. Figure 5 The dc supply has an emf of 12 V and negligible internal resistance. The current sensor and the voltage sensor behave as ideal meters. In circuit 1: • X is used as a variable resistor with a maximum resistance of 14.9 Ω • when X is set to maximum resistance, the resistance of L is 2.3 Ω. In circuit 2, X is used as a potential divider. Do not write outside the box 11 Discuss, with reference to circuit 1 and circuit 2, whether either circuit can produce all the data shown in Figure 4. Support your answer with a calculation. [4 marks] Do not write outside the box 12 Table 2 shows some values of V that are plotted on Figure 4 and corresponding results for I and for the power P dissipated in L. Table 2 V / V I / A P / W 3.30 1.07 3.53 5.17 1.32 7.69 1.59 12.2 9.58 11.47 1.94 22.3 0 2 . 4 Complete Table 2.