A-level PHYSICS Paper 1

A-level PHYSICS Paper 1 Friday 24 May 2024 Morning Time allowed: 2 hours Materials For this paper you must have: • a pencil and a ruler • a scientific calculator • a Data and Formulae Booklet • a protractor. Instructions • Use black ink or black ball-point pen. • Fill in the boxes at the top of this page. • Answer all questions. • You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages. • If you need extra space for your answer(s), use the lined pages at the end of this book. Write the question number against your answer(s). • Do all rough work in this book. Cross through any work you do not want to be marked. • Show all your working. Information • The marks for questions are shown in brackets. • The maximum mark for this paper is 85. • You are expected to use a scientific calculator where appropriate. • A Data and Formulae Booklet is provided as a loose insert. IB/M/Jun24/E10 7408/1 Section A Answer all questions in this section. box 0 1 . 1 State the names of the four fundamental interactions. [1 mark] 1 2 3 4 0 1 . 2 State the products of the decay of a free neutron. [1 mark] 0 1 . 3 Explain which of the fundamental interactions is responsible for the decay of the neutron. [2 marks] 0 1 . 4 The forces between two moving electrons cause their paths to change. Explain, using the concept of exchange particles, why the electron paths change. [3 marks] 0 2 A positive pion collides with a neutron and the following interaction is observed: + + n  + + Σ0 Σ0 is a neutral sigma particle with a strangeness of −1 The interaction can be used to deduce the classifications of the Σ0. 0 2 . 1 Identify the classifications of each particle in Table 1. Tick () the appropriate boxes for each particle. [2 marks] Table 1 Particle Baryon Hadron Lepton Meson π+ n K+ Σ0 0 2 . 2 A conservation rule predicts that the following interaction cannot occur:  + n   + Σ0 State the conservation rule. Go on to explain your answer. [3 marks] Question 2 continues on the next page Turn over ► One way in which neutral pions decay is 0  e + e+ +  0 2 . 3 Compare the rest energies of the particles involved in this decay. [2 marks] 0 2 . 4 The decay of the neutral pion leads to the production of further gamma photons. Explain why. [1 mark] 0 2 . 5 The Standard Model is a theory that classifies elementary particles. Evidence for the theory has been collected since about 1950. However, the term Standard Model has only been used since 1973. Suggest why progress in particle physics is slow. [1 mark] 0 3 Figure 1 shows two prisms A and B of different refractive indices joined to make a block. A ray of monochromatic light is shown entering and then leaving the block. Figure 1 0 3 . 1 Complete, on Figure 1, the path of the ray of light inside the block. [1 mark] 0 3 . 2 Deduce which prism, A or B, has the greater refractive index. [2 marks] The block is used with a telescope to investigate stars. The block can be replaced with a diffraction grating. 0 3 . 3 Describe one non-astronomical application of a diffraction grating. [1 mark] Question 3 continues on the next page Turn over ► 0 3 . 4 Figure 2 shows a spectrum of light. Two lines in the spectrum are labelled X and Y. Figure 2 The light passes at normal incidence through a diffraction grating. The number of lines per metre for the grating is G. The first-order diffraction angle of X is at 28.2° to the normal. Calculate G. [3 marks] G = m−1 0 3 . 5 A scientist wants to obtain an accurate value for the difference in wavelength between line X and line Y. She has two options: • option 1: to analyse the second-order spectrum from the original grating • option 2: to analyse the first-order spectrum from a grating with 2G lines per metre. Discuss which option she should choose. [3 marks] Turn over for the next question Turn over ►