Angel International School - Manipay 2 nd Term Examination March, 2018 Physics

Transcription

1 Grade 08 Angel International School - Manipay 2 nd Term Examination March, 2018 Duration: 2.00 Hours 1) Underline the correct answer: Part 1 Index No:- 1) Which is necessary for producing a sound? a) air b) vibration c) waves d) frequency 2) The diagram shows the magnetic field lines for a bar magnet. Which statement best describes the strength of the magnetic field for the bar magnet? a) The magnetic field is strongest at north pole of the magnet. b) The magnetic field is strongest at the south pole of the magnet. c) The magnetic field is strongest at both the north and south poles. d) The magnetic field is strongest in the region between the north and south poles. 3) Wave B will create a sound than wave A. a) louder b) quieter c) lower pitch d) higher pitch 4) The distance between E and H is called. a) a crest b) a wavelength c) the amplitude d) the frequency 5) Which statement correctly compares Wave A and Wave B? a) Wave A has a greater amplitude than Wave B b) Wave B has a greater amplitude than Wave A c) Wave A has a greater wavelength than Wave B d) Wave B has a greater wavelength than Wave A 6) The distance between which two points is one wavelength? a) A and E b) A and C c) D and E d) C and J 7) coal used in power plant is also known as a) steam coal b) charcoal c) coke d) soft coal 8) Inner ear is a mash up of semi-circular canals and a) Cochlea b) anvil c) hammer d) brain 9) Pinna is a shell-like structure which is a part of a) inner ear b) outer ear 10) The three ear bones are known as, a) malleus, incus and stapes b) hammer,anvil and stirrup c) both a) and b) d) hammer, uvala and femur c) middle ear d) inner-middle ear Gr8-1

2 11) The velocity of light in vaccum is a) ms -1 c) ms -1 b) ms -1 d) ms -1 12) Magnets was found in a place called a) Asia b) magnesia c) Europe d) Denmark 13) The lens used in spectacles for the correction of short- sightedness is a a) concave lens c) concavo - convex lens b) convex lens d) plano convex lens 14) A power stations does this a) converts chemical energy into mechanical energy b) converts electrical energy into mechanical energy c) converts mechanical energy into electrical energy d) converts kinetic energy into electrical energy 15) Sounds are measured in units called a) hertz(hz) b) decibels(db) 16) Line which is at right angle to surface is called a) normal ray b) incident ray c) meters(m) d) pascal(pa) c) reflected ray d) all the above 17) From the picture, It is used to find the in which ship or plane is moving. a) Distance c) signal b) direction d) temperature 18) When light is refracted through glass prism it will give a) rainbow colours c) secondary colours b) primary colorus d) cool colorus 19) Kind of shadow depends on size and position of a) Object c) both a and b b) light source d) only b 20) From the picture, what is F? a) Cochlea b) 3 bones of ear c) ear drum d) pinna 21) From the picture, which part sends sound wave messages to the brain? a) C c) D b) F d) E 22) Which of the following quality determines the loudness of a sound waves? a) Amplitude b) frequency c) vibration d) pitch 23) An image formed by the plane mirror is, a) virtual,behind the mirror and of the same size as the object. b) real, behind the mirror and of the same size as the object. c) virtual, behind the mirror and enlarged. d) real at the surface of the mirror and enlarged. 24) Cyan,Yellow and Magenta are, a) primary colours b) white colours 25) Formula for efficiency is a) Energy output + energy input b) Energy output energy input c) Energy output/energy input d) Energy input/energy output c) secondary colours d) tertiary colours (25 marks) Gr8-2

3 2) Match the column I with column II COLUMN I COLUMN II 1) Reflected ray a)middle ear 2) Magnet b)luminous object 3) Red light c)light ray that is reflected 4) Converging lens d)transparent material 5) ALNICO e)north and south pole 6) Reed switch f)primary colour of light 7) Candle flames g)biconvex lens 8) Diamond h)magnetic material 9) Ear drum i)object with smooth surface 10) Glass j)magnetic switch (5 marks) 3) Say which statement is true or false.[t or F]. 1) Electricity is a type of energy. [ ] 2) The number of oscillations per second of a vibrating object is called its time period. [ ] 3) Frequency measures the number of sound waves that pass in one second. [ ] 4) A region of darkness which is formed when path of light is blocked is called shadow. [ ] 5) Light travels at different speed in different medium. [ ] 6) In every magnet, artificial or natural has 2 magnetic poles. [ ] 7) A concave lens always forms a virtual image. [ ] 8) Electricity is generated on small scale in power stations. [ ] 9) A real image cannot be obtained on a screen. [ ] 10) A concave mirror always forms a real image. [ ] 11) We see non luminous objects by the light they reflect. [ ] 12) The pitch of a sound is related to frequency of its waves. [ ] 13) Electricity can be generated by magnetism. [ ] 14) Prey animals like rabbit, cannot turn their outer ears in many direction for approaching predators. [ ] 15) Sound waves can travel in all the three states of matter because they all contain particles.[ ] (15 marks) 1) Answer the following: Part - 2 1) Mark the parts of the HUMAN EAR and answer the following questions from the picture. (4 marks) Gr8-3

4 (i) Which part of the ear amplifies the sound waves? (ii) What happens when a sound wave hits the eardrum? (iii) Why should we not stand too close to the band at an outdoor event? (iv) Which part of an ear is filled with a fluid? (4 marks) (v) From the picture, label it and answer the following below. a) What is cochlea? b) Write the function of auditory nerve? 2) a) Identify the picture, and label it. b) From the picture, what type of switch it is? c) What is a reed? d) Name the gas which is filled in reeds? e) Say (true or false). In given picture, gas is filled because metal does not react. [ ] (4 marks) 3) Define the following terms: (ANY 5) a) Magnetic lines of force b) Bicycle dynamo c) d) Magnetic field e) Nerve deafness f) Frequency g) Shock waves. 4) a) Identify the given picture, and label it. (10 marks) b) How does an electric bell work? c) In electric bells electric energy transform into energy. Gr8-4

5 5) Identify the picture, and label it. Answer the following from the above picture. a) State the laws of reflection. _ b) What is i? c) Which ray reflects from a surface? (1mark) d) From the picture, what is X and Y? 6) a) Observe the given below picture carefully and elaborate your answers. b) How is sound produced? c) How is sound produced by humans? Gr8-5

6 d) Which part of the ear collects sound? 7) Identify the picture and label the parts where ever necessary. (i) How electricity generate by power station? (ii) Construct an energy chain to show the path of energy through power station. (iii) In generator, what is connected at the end of the shaft? ***** Gr8-6