2022 RI Prelims H2 Phy Paper 3 Sect B QP

This document consists of 8 printed pages. © Raffles Institution 9749/03 [Turn over Centre Number Index Number Name Class S3016 RAFFLES INSTITUTION 2022 Preliminary Examination PHYSICS Higher 2 Paper 3 Longer Structured Questions 9749/03 21 September 2022 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your index number, name and class in the spaces at the top of this page. Write in dark blue or black pen in the spaces provided in this booklet. You may use pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Section A Answer all questions. Section B Answer one question only and circle the question number on the cover page. You are advised to spend one and half hours on Section A and half an hour on Section B. The number of marks is given in brackets [ ] at the end of each question or part question. *This booklet only contains Section B. For Examiner’s Use Section B (circle 1 question) 7 / 20 8 / 20 Deduction

2 © Raffles Institution 9749/03 [Turn over Section B Answer one question from this Section in the spaces provided. 7 (a) Fig. 7.1 shows a stretched string connected to an oscillator at one end and a load over a smooth pulley at the other end. The length of the string between the oscillator and the pulley is L. Fig. 7.1 (i) Explain why observable stationary waves are seen on the string when the oscillator is vibrating vertically at certain discrete frequencies. [3] (ii) Show that the discrete frequencies in (a)(i) are integer multiples of 2 v L where v is the speed of the wave on the string. [1] oscillator load pulley L

3 © Raffles Institution 9749/03 [Turn over (iii) When the frequency of the oscillator is 40.0 Hz, a stationary wave with 5 nodes is seen for  0.600 mL . Calculate v. v = 1m s [2] (iv) The speed v of the wave on the string is related to the tension T in the string by vk T where k is a constant. Determine the new frequency of the oscillat or such that a stationary wave with 5 nodes is still seen on the string if the tension is decreased by 2%. new frequency = Hz [2]

4 © Raffles Institution 9749/03 [Turn over (b) (i) Fig. 7.2 shows a point source positioned a distance D from a single slit of width 0.30 mm. The point source emits monochromatic light of wavelength 600 nm. Fig. 7.2 (not to scale) 1. Show that the angle of the first minimu m of the diffraction pattern from the principal axis is 32.0 10 rad . [1] 2. Sketch on Fig. 7.3, the diffraction pattern of the light after