THE PHYSICS PROBLEMS OF EVEN SEMESTER EXAMINATION JUNIOR HIGH SCHOOOL I SELONG YEAR 2009 – 2010 Choose the correct answer ! 1. The vibration period can be calculate by T=t/n, t refer to time in second and n is number of vibration. A load in simple swing 100 times for 200 seconds. What is vibration period of the swing? a. 0,5 second b. 1,5 seconds c. 2 seconds d. 4 seconds 2. Wave velocity can be calculated with simple pattern, that is v = λ×f. λ refer to wave lenght in meter, and f refer to frequency of wave in Hz. If f same with 1/T so the pattern of wave velocity change into ... a. v = λ×T b. v = f×T c. v = λ / T d. v = f / T 3. You meet the vibration in around your home. Value of period is known 5 seconds, so the frequency of this vibration is .... a. 5 Hz b. 2,5 Hz c. 2 Hz d. 0,2 Hz 4. We know that base of the direction of vibration and spreading the wave divide into two kinds, that is transerve wave and longitudinal wave. This picture is one of wave. v The wave above include to ..... a. transerve wave b. longitudinal wave wave c. spring wave d. potential 5. Sea water wave travels with velocity 32 meter/second forming wave of total lenght 24 meter like shown by the picture. 24 m The magnification of wave frequency is .... a. 6 Hz b. 4 Hz c. 3 Hz d. 2 Hz 6. This is a simple pendulum to describe the vibration. x y z Consider the figure, what vibration is done by pendulum if simple pendulum moves from xy-z-y-x-y-z ? a. 1 vibration b. 1½ vibrations c. 2 vibration d. 2½ vibrations 7. Sound wave can spread in solid, liquid, and gas. Base of experiment, the sound wave has fastest velocity when spreads in .... a. solid b. gas c. liquid d. gel matter 8. We know that if a light hits a body surface commonly will be reflected. Now, please you look picture follow. y t ra re fle ct ed ra y n ide inc c d a b The incident angle is shown by letter ... a. b b. c c. d d. a 9. Base of the magnifiaction wave frequency the sound wave divide be three kinds, that is infrasound (< 20 Hz), audiosound (20 Hz – 20.000 Hz), and ultrasound (20.000 Hz <). If sound wave period is 0,0001 second, its mean this sound include to .... a. infrasound b. audiosound c. supersound d. ultrasound 10. Sound has several properties, one of them namely ... a. sound can spread in vacuum b. sound can spread without medium c. sound is longitudinal wave d. sound is trnaserve wave 11. In kentongan is made hole in the middle so the air enters in kentongan. When it is hit the sound of kentongan becomes louder. Loud sound from kentongan is resulted by symptom ... a. reflection of wave c. refraction of wave b. resonance of wave d. polarization of wave 12. Sound wave beside can spread, can also be reflected if the sound wave hits hard surface, such as wall or stone. In everyday life, it is found the phenomenon of wave reflection as follow, exept .... a. echo which is happening in the cave c. the tone thet changes in musical instrument b. reverberation in cinema room d. wavelenght received by antenna 13. A child shouts to reflector wall, 4 seconds later is heard reflection sound. If sound velocity at that time is 340 m/s, so the distance of the child with reflector wall is .... a. 85 meters b. 170 meters c. 680 meters d. 1360 meters 14. You stand up 5 meters infront of flat mirror. Then, you move to avoid from mirror as far as 3 meters. The distance of the first your image to last your image is ..... a. 3 meters b. 5 meters c. 8 meters d. 10 meters 15. The convex mirror has others name that is divergent mirror and negative mirror. The divergent mirror its mean ... a. the convex mirror can concentrate several ray b. the convex mirror experiences ray reflection c. the convex mirror can disseminate several ray d. the convex mirror can disentangle several ray 16. The correct illustration about special ray from concave mirror is ... A b M f c M f d M f M f 17. Reflected angle is formed by reflected ray and normal line and incident angle is formed by incident ray and normal line. n ide inc y t ra 67o ed ct fle re y ra The magnification reflected angle from picture above is .... a. 113o b. 67o c. 30o d. 23o 18. A body of height 8 cm is located 24 cm infront of convex mirror. If focus distance of the convex mirror is 10 cm, the following properties of image are true, except ... . a. virtual c. upright and virtual b. upright and enlarged d. located behind mirror 19. Look at the picture! 1 2 AIR WATER 3 AIR 4 AIR AIR WATER WATER WATER The correct illustration about refraction rays is ... a. picture number 1 c. picture number 3 b. picture number 2 d. picture number 4 20. The convex mirror forms virtual and upright image. Sony has a convex mirror which radius of curvature is 60 cm. If he puts an object at 15 cm from the convex mirror so image distance is ... a. 10 cm behind the mirror c. 10 cm infront of the mirror b. 4 cm behind the mirror d. 4 cm infront of the mirror 21. A concave mirror has focus distance of 12 cm. To form real image enlarged of 4 times so object distance to the mirror is ... . (national evaluation) a. 8 cm b. 15 cm c. 20 cm d. 30 cm 22. A body is located 6 cm infront of a concave mirror so formed the real image of distance 30 cm from the mirror. Focus distance of the mirror is ... . a. 36 cm b. 24 cm c. 6,2 cm d. 5 cm 23. Look at the picture ! Base of this illustration, the incident rays disseminated by the lens. What is name of this lens? a. concave lens c. convex lens b. plan-concave lens d. plan-convex lens 24. There are three eyes defect that is myopia, hypermetropia, and presbyopia. The hypermetropia can helped by ... . a. positive lens b. negative lens c. bifocal lens d. flat lens 25. To determine focus distance of convex lens can use the formula 1/f = 1/so + 1/si. The illustration below shows the procces of formation the real image by a lens. 12 cm (+) 24 cm The focus distance and power of lens is ... . a. 8 cm and +12,5 diopters c. 12 cm and +8⅓ diopters b. 10 cm and +10 diopters d. 24 cm and +25/6 diopters 26. The concave lens forms image with properties virtual, upright, and enlarged. The correct illustration about image formation by concave lens is ... . a b c d f M f f f f f f f 27. Astronomical telescope is an optical instrument used to observe objects in the sky, such as moon, planets, or another objects in the sky. This telescope consist of two convex lenses that is an objective lens and an ocular lens, with focus distance of the objective lens is larger than focus distance of the ocular lens. The power of objective lens is 2 diopters and ocular lens has power of 50 diopters. The magnification of image is ... . a. 100 times b. 52 times c. 48 times d. 25 times 28. A student sits rearmost in his class. When he sees writing on the whiteboard is seen not clear, while his friend of adjacent chair can see clearly. Means that student suffers eye defect of myopia. The correct illustration for myopia is ... . a b c d 29. Microscope consist of two lens, that is an objective lens and an ocular lens. The objective lens is lens that faces to object directly, while the ocular lens is lens near to eyes. Both are included kinds of ... . a. divergent lens b. negative lens c. convergent lens d. concave lens 30. A book contains small writing so it is not clearly seen. To be able to see it is used a magnifying glass of focus distance is 6 cm. If the magnifying glass is put 5 cm on the book, the image magnification formed by the magnifying glass is ... . a. 2 times b. 6 times c. 3 times d. 5 times