QUESTION BANK. with Complete Solutions. Based on Latest SCERT Textbook issued by Department of Education, Government of Kerala in 2016.

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2 Strictly as per the Latest Syllabus and Design Prescribed by SCERT Kerala Education Board KERALA SSLC FOR 017 EXAM QUESTION BANK with Complete Solutions CLASS 10 PHYSICS (PART 1) Based on Latest SCERT Textbook issued by Department of Education, Government of Kerala in 016 Published by : Ph.: Fax : website :

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4 CONTENTS 1. WAVE MOTION 5-1 Topic-1 : Waves and their Classification Topic- : Sound and its Characteristics Topic-3 : Reflection of Sound-Echo and Reverberation. EFFECTS OF ELECTRIC CURRENT 13-0 Topic-1 : Electric Current Topic- : Heating Effect of Electric Current Topic-3 : Lighting Effect of Electric Current Topic-4 : Electric Energy and Power 3. ELECTROMAGNETIC INDUCTION 1-7 Topic-1 : Electromagnetic Induction Topic- : A.C. Generator and Microphone Topic-3 : Mutual and Self Induction Topic-4 : Transformer 4. POWER TRANSMISSION AND DISTRIBUTION 8-33 Topic-1 : Power Generation and Transmission Topic- : Power Distribution and Safety 5. HEAT Topic-1 : Kinetic Theory, Heat and Temperature Topic- : Principle of Mixtures, Change of State and Global Warming qq ( 3 )

5 PREFACE Malcolm Forbes said Education's purpose is to replace an empty mind with an open one and this is something which is always followed by Government of Kerala, Department of Education, whether through their education system framework or recent enhancement in their curriculum. The aim of their Curriculum is not just to let learners obtain basic knowledge but to make them lifelong learners. The purpose of this book is to nurture individuality and thus enhance one's innate potentials which help in increasing the self-study mode for students. This book strengthens knowledge and attitude related to subject. This book is designed in such a way that students can set their own goals and can improve their problem solving and thinking skills. This book is strictly as per the latest SCERT Kerala Textbook, introduced by SSLC Board in 016. It follows the latest syllabus prescribed by the board. It contains all types of questions like Textbook Questions, VSA Questions (Very Short Answer), SA Questions (Short Answer), MCQs (Multiple Choice Questions) and LA Questions (Long Answer). A synopsis is given for every chapter which contains important points from that chapter. Each chapter has high quality figures wherever required for better, fast and clear understanding. OSWAAL SSLC Question Bank is different and better in terms of High Quality Questions which are developed by 'OSWAAL Expert Panel' which ensures success in examination. The Question Bank is arranged Topic-Wise where each topic from every chapter is explained in detail. High quality figures and Flow charts are given to improve retention of concepts. Through OSWAAL Books students are taught how to think, not what to think. We at OSWAAL Books try to use quality content, standard language, creativity and high quality figures, which makes readers to enjoy it because we believe if our readers don't enjoy reading our book then there is no use in reading it at all. This is one of the reasons that the scope of this book extends from students to teachers. Teachers can use this book as a perfect teaching guide and students can use this book for good learning and practice. At last we would like to thank our authors, editors, reviewers and specially students whom we request to send suggestions regularly which will help in continuous improvement of this book and will make this book One of the Best. Wish you all Happy Learning. Why Topic Wise Question Banks Are A Better Choice than Previous Year s Papers? Publisher Question Banks 1. Chapter-wise and Topic wise presentation in Question Banks facilitates systematic study.. Question Banks can be referred to by the students throughout the year as well as at the completion of each chapter in school. 3. Question Banks, take into account any changes in syllabus or layout and hence are fully updated and aligned as per the latest specifications by the Board. Previous Years Papers 1. Year Wise presentation restricts methodical flow of learning.. These can be referred to only after the completion of the full syllabus in school. 3. Previous Years' questions cannot be changed and hence fail to be adept with the latest Board specifications ( 4 )

6 CHAPTER 1 WAVE MOTION SYLLABUS Waves and their Classification Reflection of Sound Echo and Reverberation Sound and its Characteristics TOPIC-1 Waves and their Classification QUICK REVIEW Waves can be classified mainly into two types : z Mechanical waves z Electromagnetic waves When a wave travelling in one medium passes to another medium, the speed and wavelength of wave changes but frequency remains same. During wave propagation, only energy flows from one point to another, medium particles only oscillate about-their mean position. Relationship between speed of sound, its frequency and wave length is given by : Speed = Frequency Wavelength KNOW THE TERMS TOPIC - 1 Waves and their Classification...P. 5 TOPIC - Sound and its Characteristics...P. 8 TOPIC - 3 Reflection of Sound-Echo and Reverberation...P. 11 Wave Motion : It is the propagation of disturbances produced on one part of a medium by the vibrations of its particles, to all the other parts. Mechanical Waves : These waves necessarily require material medium for their propagation. These waves travel in the medium through the vibrations of medium particles about their mean position. These waves are classified as longitudinal waves and transverse waves. Electromagnetic Waves : These are formed by the periodic vibration of mutually perpendicular electric and magnetic fields in a plane normal to the direction of wave propagation. A medium is not essential for its propagation, and they are transverse in nature. Longitudinal Waves : A wave in which the particles of the medium vibrate in the direction parallel to the direction of propagation of the wave. This creates compressions and rarefactions alternately in the medium. Transverse Waves : A Wave in which the particles of the medium vibrate in a direction perpendicular to the direction of propagation of the wave, forming crests and troughs.

7 6 ] Oswaal Kerala SSLC Question Bank, PHYSICS, Class X Wavelength : It is the distance between two consecutive particles which are in the same phase of vibration. This is equivalent to the distance advanced by the wave by the time a particle has completed one vibration. It is denoted by l. The unit of wavelength is metre (m). Amplitude : It is the maximum displacement of a particle from its mean position. It is denoted by letter a. Its units is metre (m). Frequency : It is the number of vibrations occurred in one second. Number of vibrations Frequency = Time taken The unit of frequency is Hertz (Hz). Time Period : The time taken by a particle to complete one vibration or oscillation. It is denoted by T. Its unit is second. Very Short Answer Type Questions (1 mark each) Q.1. Two waves A and B have wavelength of m and 5 m respectively. Which one of them has higher frequency. 1 Ans. As we know that, Frequency Wavelength Wave A has higher frequency. Q.. If frequency of a wave is 0 Hz, what is the time period of vibration? Ans. Since T = 1 f Given that f = 0 Hz 1 T = sec = 0 05 sec 0 Q.3. Which type of wave contains compressions and rarefactions in the medium? Ans. Longitudinal wave. Q.4. Which property of wave remains invariant while travelling from one medium to another? Ans. Frequency. Q.5. On what factors the speed of a wave depends on? Ans. Elasticity and density of the medium. Q.6. On what factors does the speed of wave in a stretched string depends? Short Answer Type Questions -I Q.1. Write the differences between transverse waves and longitudinal waves. Ans. S. No. Transverse Waves Longitudinal Waves 1. Particles of the medium Particles of the vibrate normal to medium vibrate the direction of along the direction propagation of waves. of propa- gation of waves.. Crests and trough are formed. 3. Examples are : Waves on the surface of liquids, electromagnetic waves. Compressions and rarefactions are formed. Examples are : Sound waves in air or inside a liquid. Ans. Tension in the string and mass per unit length of string. Q.7. What are longitudinal waves? Ans. A wave in which the particles of the medium vibrate in a direction parallel to the direction of propagation of the wave. This creates compressions and rarefactions alternately in the medium. For example sound waves. Q.8. What are transverse waves? Ans. A transverse wave is a wave in which the particles of the medium vibrate in a direction perpendicular to the direction of propagation of the wave. This creates crests and troughs. For example waves on the surface of water. Q.9. Define wavelength with reference to a longitudinal wave. Ans. The distance between corresponding points of two consecutive compressions or two consecutive rarefactions is the wavelength of the longitudinal wave. Q.10. If frequency of a wave is increased, what happens to its wavelength? 1 Ans. Since, Wavelength Frequency Wavelength decreases with increase in frequency. ( marks each) Q.. If speed of a wave in a medium is 350 m/s and wavelength 7 m, find the time period of one vibration. Ans. Given that v = 350 m/s, λ = 7 m We know that v = f λ v 350 f = = = 50 Hz λ 7 Also, 1 1 T = = sec f 50 T = 0 0 sec Q.3. The diagram ahead shows displacement-time graph of a wave travelling in a string with velocity 0 m/s. Use graph to calculate the frequency and wavelength of the wave.

8 WAVE MOTION [ 7 y O A 005. B C t (sec) Ans. From the graph, one wavelength is from O to B. T = 0 10 sec 1 1 (i) Frequency, f = = = 10 Hz T 0.10 (ii) Given, Speed of Wave = 0 m/s v Applying formula, λ= f 0 λ= = m 10 Q.4. The graph below shows the displacement distance graph of a wave travelling in a medium with velocity 40 m/s. Calculate the frequency and wavelength of the wave. y O A 1 B 3 C x (in m) Ans. (i) One wavelength completes from O to B Wavelength = m (ii) Given that, speed = 40 m/s We know that, speed = Frequency Wavelength 40 = f 40 f = = 0 Hz Q.5. State two factors on which the speed of a wave travelling in a medium depends. Ans. The speed of a wave travelling in a medium depends on: (i) Elasticity of the medium (E) (ii) Density of the medium (d) v = E d Q.6. State the differences between light waves and sound waves. Ans. S. No. Light Waves 1. These are electromagnetic waves.. They are transverse in nature. Sound waves These are mechanical waves. They longitudinal nature. are in 3. They form crests and troughs. 4. They do not require material medium for their propagation. 5. They travel with a speed of m/s in air or vacuum. They form compressions and rarefactions. They require material medium for their propagation. They travel with a speed of 340 m/s in air. Q.7. Define the following terms in relation to a wave : (a) Amplitude (b) Frequency (c) Wavelength (d) Wave velocity Ans. (a) Amplitude : It is the maximum displacement of a particle from its means position. Its unit is metre. Q.8. Displacement (b) Frequency : If is the number of vibrations in one second. Number of Vibrations Frequency= Time taken Its unit is hertz (Hz). (c) Wavelength : It is the distance between two consecutive particles which are in the same phase of vibration. Its unit is metre. (d) Wave velocity : It is the velocity of the wave by which it propagates in a medium. Its unit is m/s. O Wave velocity = Wavelength Frequency Distance (m) Calculate the frequency of the wave, represented graphically above, if it travelled a distance of 1 m in 0 5 sec. Ans. From the graph, wavelength = 4 m Given, Distance = 1 m time = 0 sec 1 Wave velocity = = 48 m/s 0 5 We know that, v = λ f 48 = 4 f f = 1 Hz.

9 8 ] Oswaal Kerala SSLC Question Bank, PHYSICS, Class X TOPIC- Sound and its Characteristics QUICK REVIEW Sound is a form of energy, produced by a body when if vibrates, requires a material medium for its propagation. Audible range of normal human being is from 0 Hz to 0,000 Hz. Sound waves of frequencies below 0 Hz are called infrasonic waves. Sound waves of frequencies above 0,000 Hz are called ultrasonic waves. Speed of sound in different medium is different. Speed of sound in solids > speed in liquids > speed in gases. Higher the frequency more shrill is the sound. The natural frequency of a body depends on shape and size of the body. The amplitude of forced vibrations depends on the frequency of the external force. If frequency of external force is different from the natural frequency of the body, the amplitude of oscillation is very small. But if the frequency of the external force is exactly equal to the natural frequency of vibrating body, the amplitude of oscillations is very large Amplitude of forced vibration does not change with time. Two sounds can be distinguished from one another by the three different characteristics : z Loudness z Pitch (Shrillness) z Quality (timbre) Loudness of sound depends on amplitude of the wave. The louder sound corresponds to the wave of larger amplitude. Pitch is that characteristic of sound by which an acute (or shrill) note can be distinguished from a grave or flat note. It depends on frequency of sound wave. Factors affecting the loudness of sound are : z Loudness is proportional to the square of amplitude. z Loudness varies inversely as the square of distance. z Loudness depends on surface area of the vibrating body. z Loudness depends on density of medium. z Loudness depends on the presence of resonant bodies. KNOW THE TERMS Free (or Natural) Vibrations : The periodic vibrations of a body of constant amplitude in the absence of any external force on it, are called the free vibrations. Damped Vibrations : The periodic vibrations of body of decreasing amplitude in presence of a resistive force are called damped vibrations. Forced Vibrations : The vibrations of a body which takes place under the influence of an external periodic force acting on it are called forced vibrations. Resonance : When the frequency of an externally applied periodic force on a body, is equal to its natural frequency, the body readily begins to vibrate with an increased amplitude. This phenomenon is known as resonance. Loudness : It is the property by virtue of which a loud sound can be distinguished from a faint one; it depends on amplitude of the wave. Larger the amplitude of wave louder is the sound. Quality (Or Timbre) : Quality (or timbre) of a sound is that characteristic which distinguishes the two sounds of the same loudness and same pitch, but emitted by two different instruments. The quality of a musical sound depends on the wave form.

10 WAVE MOTION [ 9 Very Short Answer Type Questions (1 mark each) Q.1. State one condition for a body to execute free vibration. Ans. Absence of any resistive force like medium. It can occur only in vacuum. Q.. Name one factor on which the frequency of sound emitted due to vibrations in an air column depends. Ans. Length of air column. Q.3. What adjustments would you make for tuning a stringed instrument for it to emit a desired frequency? Ans. Change the tension in the string. Q.4. Explain why strings of different thickness are provided on a stringed instrument? Ans. Natural frequency of vibrations of a stretched string is inversely proportional to the radius (or thickness) of string, so notes of different frequencies can be produced by vibrating different strings. Q.5. A blade, fixed at one end, is made to vibrate by pressing, its other end and then releasing it. State one way in which the frequency of vibrations of the blade can be lowered. Ans. By increasing the length of the blade or by sticking a small weight on the blade at its free end. Q.6. How does the medium affect the amplitude of free vibrations of a body? Ans. Medium provides resistive force to the vibrating body, thus decreasing the amplitude of free vibration. Q.7. State the condition for the resonance to occur. Ans. Frequency of the externally applied force must be equal to the natural frequency of the vibrating body. Short Answer Type Questions-I Q.1. What is meant by the natural frequency of vibration of a body? Name two factors on which it depends. Ans. The natural frequency of an object is the frequency at which it vibrates freely. It depends on : (i) Shape of the body. (ii) Size or structure of the body. Q.. When a troop crosses a suspension bridge the soldiers are asked to break steps. Explain the reason. Ans. When soldiers march in steps, each soldier exerts a periodic force in same phase and therefore bridge executes the forced vibrations of frequency of their steps. If the natural frequency of brigde happens to be equal to the frequency of the steps, the bridge will vibrate with a large amplitude due to resonance and the suspension bridge may collapse. Q.8. Name three characteristics of a musical sound. Ans. The three characteristics of a musical sound are loudness, pitch and quality. Q.9. Name the quality of sound wave which determines the loudness. Ans. Amplitude of the sound wave. Q.10. If the amplitude of a wave is doubled, what will be the effect on its loudness Ans. As, Loudness (Amplitude) Loudness will become 4 times. Q.11. Why is the loudness of the sound heard by a plucked wire increased when it is mounted on a sound board? Ans. As loudness depends on the surface area of the vibrating body, hence, by increasing surface area, loudness increases. Q.1. What determines the pitch of a sound? Ans. Frequency of the vibrating body determines the pitch of a sound. Q.13. How is it possible to detect the filling of a bottle under a water tap by hearing the sound at a distance? Ans. As water level rises in the bottle, the length of air column decreases, thereby increasing the frequency of the sound emitted which can easily be detected. Q.14. Name the characteristic which enables one to distinguish the sound of two musical instruments even if they are of same pitch and same loudness. Ans. Quality or timbre which depends on their respective wave forms. ( marks each) Q.3. State two ways of increasing the frequency of vibrations of a stretched string. Ans. (a) By increasing the tension in the string. (b) By decreasing the length of the string. Q.4. Two waves of the same pitch have amplitudes in the ratio 1 : 3. What will be the ratio of their (i) Loudness, (ii) frequencies. Ans. (i) Loudness (amplitude) Ratio of loudness = 1 : 9 B Frequency ~ Pitch Since two waves have same pitch. Ratio of frequencies = 1 : 1 Q.5. How does the wave pattern of a loud note differ from a soft note? Draw a diagram. Ans. Wave pattern of a loud note differ in amplitude from a soft-note. The louder sound has larger amplitude.

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