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with Complete SolutionsQUESTION BANK
CLASS 10PHYSICS(PART – 1)
Strictly as per the Latest Syllabus and DesignPrescribed by SCERT Kerala Education Board
KERALA SSLC
FOR2017
EXAM
Based on Latest SCERT Textbook issued by Department of Education, Government of Kerala in 2016
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( 3 )
1. WAVE MOTION 5 - 12
Topic-1 : Waves and their Classification
Topic-2 : Sound and its Characteristics
Topic-3 : Reflection of Sound-Echo and Reverberation
2. EFFECTS OF ELECTRIC CURRENT 13 - 20
Topic-1 : Electric Current
Topic-2 : Heating Effect of Electric Current
Topic-3 : Lighting Effect of Electric Current
Topic-4 : Electric Energy and Power
3. ELECTROMAGNETIC INDUCTION 21 - 27
Topic-1 : Electromagnetic Induction
Topic-2 : A.C. Generator and Microphone
Topic-3 : Mutual and Self Induction
Topic-4 : Transformer
4. POWER TRANSMISSION AND DISTRIBUTION 28 - 33
Topic-1 : Power Generation and Transmission
Topic-2 : Power Distribution and Safety
5. HEAT 34 - 40
Topic-1 : Kinetic Theory, Heat and Temperature
Topic-2 : Principle of Mixtures, Change of State and Global Warming
CONTENTS
( 4 )
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PREFACE
CHAPTER
1 SYLLABUS� Waves and their Classification � Sound and its Characteristics� Reflection of Sound Echo and Reverberation
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
� 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.
TOPIC - 1Waves and their Classification ....P. 5
TOPIC - 2Sound and its Characteristics ....P. 8
TOPIC - 3Reflection of Sound-Echo and Reverberation ....P. 11
WAVE MOTION
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 2 m and 5 m respectively. Which one of them has higher frequency.
Ans. As we know that, Frequency
1Wavelength
∝
∴ Wave A has higher frequency. Q.2. If frequency of a wave is 20 Hz, what is the time
period of vibration ?
Ans. Since =1
Tf
Given that f = 20 Hz
⇒ 1
T sec 0 05 sec20
= = ⋅
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 ?
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 ?
Ans. Since, Wavelength
1Frequency
∝
∴ Wavelength decreases with increase in frequency.
Short Answer Type Questions -I (2 marks each)
Q.1. Write the differences between transverse waves and longitudinal waves.
Ans.
S. No.
Transverse Waves Longitudinal Waves
1. Particles of the medium vibrate normal to the direction of propagation of waves.
Particles of the medium vibrate along the direction of propa- gation of waves.
2. Crests and trough are formed.
Compressions and rarefactions are formed.
3. Examples are : Waves on the surface of liquids, electro-magnetic waves.
Examples are : Sound waves in air or inside a liquid.
2 Q.2. 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, l = 7 m We know that v = f × l
⇒ 350
50 Hz7
vf = = =
λ
Also,
1 1T sec
50f= =
T = 0⋅02 sec 2 Q.3. The diagram ahead shows displacement-time
graph of a wave travelling in a string with velocity 20 m/s. Use graph to calculate the frequency and wavelength of the wave.
WAVE MOTION [ 7
Ct (sec)
0 15.0 10.0 05.
A B
O
y
Ans. From the graph, one wavelength is from O to B. ∴ T = 0·10 sec
(i) Frequency, = = =1 1
10 HzT 0.10
f
(ii) Given, Speed of Wave = 20 m/s
Applying formula,
vf
λ =
202 m
10λ = = 2
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.
C
x (in m)
3
2
1
A
B
O
y
Ans. (i) One wavelength completes from O to B ∴ Wavelength = 2 m (ii) Given that, speed = 40 m/s We know that, speed = Frequency × Wavelength 40 = f × 2
⇒ 4020 Hz
2f = = 2
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)
=
Ev
d 2
Q.6. State the differences between light waves and sound waves.
Ans. S. No.
Light Waves Sound waves
1. These are electromagnetic waves.
These are mechanical waves.
2. They are transverse in nature.
They are longitudinal in nature.
3. They form crests and troughs.
They form compres-sions and rare-factions.
4. They do not require material medium for their propagation.
They require material medium for their propagation.
5. They travel with a speed of 3 × 108 m/s in air or vacuum.
They travel with a speed of 340 m/s in air.
2 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.
(b) Frequency : If is the number of vibrations in one second.
Number of VibrationsFrequency=
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.
Wave velocity = Wavelength × Frequency. 2 Q.8.
Distance (m)
641 2O
Dis
pla
cem
ent
53
Calculate the frequency of the wave, represented graphically above, if it travelled a distance of 12 m in 0·25 sec.
Ans. From the graph, wavelength = 4 m Given, Distance = 12 m time = 0·2 sec
∴ Wave velocity 1248 m/s
0 25= =
⋅
We know that, v =l× f ⇒ 48 = 4 × f ⇒ f = 12 Hz. 2
8 ] Oswaal Kerala SSLC Question Bank, PHYSICS, Class – X
TOPIC-2
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 20 Hz to 20,000 Hz. � Sound waves of frequencies below 20 Hz are called infrasonic waves. � Sound waves of frequencies above 20,000 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.
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.2. 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.
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)2
∴ 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.12. 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.
Short Answer Type Questions-I (2 marks each)
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. 2 Q.2. 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. 2
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. 2 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)2
∴ Ratio of loudness = 1 : 9 B Frequency ~ Pitch Since two waves have same pitch. ∴ Ratio of frequencies = 1 : 1 2 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.
Oswaal Kerala SSLC Question Bank ForClass 10 Physics (Part-1) With
Complete Solutions For 2017 Exam
Publisher : Oswaal Books ISBN : 9789386177513 Author : Panel Of Experts
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