Section 3 Waves Revision Questions and Answers Q1: The diagram represents the electromagnetic spectrum. Gamma-rays X-rays Ultraviolet Visible Infra-red Microwaves Radio waves (a) Which of X-rays and radio waves has the longer wavelength? ANS.- Radio waves (b) Which of X-rays and radio waves has the higher frequency? ANS. -X-rays (c) State one use of X-rays. ANS. - Observing internal structure of objects/ medical applications - Looking at bones/ body scans (d) State one property that all electromagnetic waves have in common. ANS. -Same speed -Travel in a vacuum -Both transverse -Can be polarized. (e) State the law of reflection. ANS. Angle of incidence = angle of reflection or incident and reflected rays and normal all in same plane (f) A teacher wants to demonstrate the law of reflection to his class. Suggest two reasons why he should use visible light rather than X-rays. ANS. – Visible ora - X-ray are dangerous ora - Equipment not readily available ora Q2: The diagram shows an example of an analogue signal and an example of a digital signal. Complete the sentences. (a)The analogue signal varies continuously between a maximum and minimum value. (b)The digital signal only has two values. These are 1 which corresponds to ON and Zero which corresponds to OFF. Q3: (a) Astudent uses a rectangular glass block to determine the refractive index of the glass. Describe the experiment. Draw a diagram to illustrate your answer. ANS. Any of the following Glass block (placed) on a suitable background Either use of ray box or use of pins and eye Position of block and rays marked or shown on 3 (i) State the relationship between i r and refractive index n.(ii) Calculate a value for refractive index using set 1. Refractive index = sin 50/ sin30=1.532 (iii)State why set 2 give a less reliable value. The angles are small and difficult to measure accurately. Q27: The diagram shows a waveform on an oscilloscope screen. The time base is set at 0.02s per division. Determine the frequency of this wave and give its unit. Frequency =1/0.02=50Hz A teacher demonstrated a method for determining the speed of sound. He hit two metal together to produce a sound. The sound was detected by two microphones connected to oscilloscope. The screen of the oscilloscope showed two signals A and B corresponding to the sound received by the two microphones. The time between the signals was 0.002s and the distance between the microphones was 0.680 m. (i) Calculate the speed of sound in m/s. Frequency = 2/0.002=1000Hz wavelength = 0.680m Using v = f λ Speed = 680 m/s (ii) State which property of a sound wave is represented by the amplitude of the signals. Loudness. (iii) Suggest an explanation for the relative sizes of the amplitudes of A and B. The tow metals produced sound of two different volumes. A is louder than B. [...]
Attached pdf document “section-3-wave.pdf” contains approx. 26 Questions from past IGCSE Physics Past Paper (IGCSE is UK exam, aimed at approximately 16 year old teenager, it is a High School Exam at pre-A level, Pre-University level. I need perfect model answers for all the questions. Noted that for most of the questions, the examiner report or marking scheme is already attached. Thus part of your effort is as simple as copying the answer into the appropriate place. Yet, the marking scheme is in points forms, not full sentence. There no drawing or further explanation. I also attached a WORD document “section-3-wave.doc”. This word document is derived from pdf using PDF to WORD conversion software. (Warning: if discrepancy between pdf version and word version, please refer to pdf which is the source” JOB: • The writer should write perfect model answers for all the questions. • The answers should be typed into the WORD document “section-3-wave.doc”. • Drawing and special formula cannot be typed easily should be made using either powerpoint or other drawing software. However, the completed drawing relevant to the answers of that specific questions should be converted to JPEG and insert (embedded) into the same word document. • The typed answers should be typed using BLUE FONT (keeping the question as BLACK FONT) Notes 1. It is high school Physics only 2. USD 200 is offered for the answers 3. Extra 100 is offered for efforts in formatting the answers (blue fonts) and embedded the answers into the WORD document. 4. TOTAL OFFER is thus USD 300. 5. The final outcome is that: the student will read through the “SINGLE” WORD document “section-3-wave.doc” for revision, where there are BOTH questions (in black) and MODEL ANSWERS (in BLUE words, full sentences as appropriate, and drawing jpeg) and Marking schemes (for some questions) 6. This is make the student very easy to revise the topics. 7. The reasons I convert the PDF to WORD document is that I found most writer very difficult to write on the PDF. WORD is easier to insert answers and insert drawing, etc. 8. SOME questions from different years past paper are very similar. You should write answers for all questons even there will be some repetition as some questions are very similar.