{"id":34605,"date":"2022-11-18T19:23:24","date_gmt":"2022-11-18T13:53:24","guid":{"rendered":"https:\/\/tsboardsolutions.com\/?p=34605"},"modified":"2022-11-18T19:23:24","modified_gmt":"2022-11-18T13:53:24","slug":"ts-inter-2nd-year-physics-study-material-chapter-1","status":"publish","type":"post","link":"https:\/\/tsboardsolutions.com\/ts-inter-2nd-year-physics-study-material-chapter-1\/","title":{"rendered":"TS Inter 2nd Year Physics Study Material Chapter 1 Waves"},"content":{"rendered":"

Telangana TSBIE\u00a0TS Inter 2nd Year Physics Study Material<\/a> 1st Lesson Waves Textbook Questions and Answers.<\/p>\n

TS Inter 2nd Year Physics Study Material 1st Lesson Waves<\/h2>\n

Very Short Answer Type Questions<\/span><\/p>\n

Question 1.
\nWhat does a wave represent?
\nAnswer:
\nA wave is a disturbance which moves through a medium.<\/p>\n

Waves transmit energy without trans-mitting matter. So waves will carry energy from one place to another place.<\/p>\n

Question 2.
\nDistinguish between longitudinal and transverse waves.
\nAnswer:
\nLongitudinal wave :
\nIf the particles of the medium vibrate parallel to the direction of propagation of the wave then that wave is called “longitudinal wave”.
\nEx : Sound waves in air.<\/p>\n

These waves can be produced in solids, liquids and gases.<\/p>\n

Transverse wave :
\nIf the particles of the medium vibrate perpendicular to the direction of propagation of the wave, then that wave is called “transverse wave”.
\nEx : Waves on a stretched string.<\/p>\n

These waves can be produced only in solids.<\/p>\n

Question 3.
\nWhat are the parameters used to describe a progressive harmonic wave?
\nAnswer:
\nFor a progressive wave (y) = a sin (\u03c9t – kx)
\nThe parameters in the above equation
\n1) a = Amplitude
\n2) \u03c9 = Angular velocity
\n3) \u03c5 = Frequency
\n4) T = Time period
\n5) \u03bb = Wavelength
\n6) v = Velocity (v)
\n7) \u03a6 = Phase
\n8) K = Propagation constant.<\/p>\n

Question 4.
\nObtain an expression for the wave velocity in terms of these parameters.
\nAnswer:
\nWave velocity :
\nIt is the distance travelled by the disturbance (energy) along the wave in one second. It is represented by V.
\nWave Velocity ‘v’
\n\"TS<\/p>\n

Question 5.
\nUsing dimensional analysis obtain an expression for the speed of transverse waves in a stretched string.
\nAnswer:
\nSpeed of transverse wave in a stretched string depends on tension (T) and linear density (\u00b5).
\nLet v \u221d Ta<\/sup> \u00b5b <\/sup>;
\nDimension of velocity (v) = LT-1<\/sup>
\nDimension of tension (T) = MLT-2<\/sup> ;
\nLinear density (p) = ML-1<\/sup>
\n\u2234 v = K Ta<\/sup> \u00b5b<\/sup>
\nWhere k is a dimensionless constant.
\nLT-1<\/sup> = K (MLT-2<\/sup>)a<\/sup> (ML-1<\/sup>)b<\/sup>
\n= Ma<\/sup> La<\/sup> T-2a<\/sup> Mb<\/sup> L-b<\/sup>
\nM\u00b0L1<\/sup>T-1<\/sup> = Ma + b<\/sup> La-b<\/sup> T-2a<\/sup>
\nEquating the powers of mass, length and time,
\na + b = 0, a – b = 1 \u21d2 – 2a = – 1
\n\"TS<\/p>\n

\"TS<\/p>\n

Question 6.
\nUsing dimensional analysis obtain an ex-pression for the speed of sound waves in a medium.
\nAnswer:
\nSpeed of sound depends on wavelength and time period. v \u221d \u03bba<\/sup> Tb<\/sup>
\nDimensions of Velocity (v) = LT-1<\/sup>;
\nDimensions of Wavelength (\u03bb) = L;
\nDimensions of Time period (T) = T;
\nL\u00b9T-1<\/sup> = La<\/sup>Tb<\/sup>
\na = 1, b = – 1 ; v = \u03bb\u00b9 T-1<\/sup>
\nv = \\(\\frac{\\lambda}{\\mathrm{T}}\\)<\/p>\n

Question 7.
\nWhat is the principle of superposition of waves?
\nAnswer:
\nWhen two waves are pulses overlap at a point the resultant displacement is the al\u00acgebraic sum of displacements due to each wave. Their resultant is also a wave.
\ny = (y1<\/sub>+ y2<\/sub>)<\/p>\n

Question 8.
\nUnder what conditions will a wave be reflected?
\nnswer:
\nWave well be reflected if it falls on a rigid surface. Because at rigid surface the particles of medium does not vibrate.<\/p>\n

If a wave falls on the interface of two different elastic media, than a Part of two different elastic media, than a part of wave is reflected and a part of incident wave will be refracted. During refraction they obey Snell’s Law.<\/p>\n

Question 9.
\nWhat is the phase difference between the incident and reflected waves when the wave is reflected by a rigid boundary?
\nAnswer:
\nAt rigid boundary phase difference between the incident and reflected wave = 180\u00b0 (or) (\u03c0). Because at rigid boundary a node is formed.<\/p>\n

Question 10.
\nWhat is a stationary (or) standing wave?
\nAnswer:
\nWhen two progressive waves having same wavelength, amplitude and frequency travelling in the medium in opposite directions superposed stationary waves are formed.<\/p>\n

\"TS<\/p>\n

Question 11.
\nWhat do you understand by the terms ‘node’ and ‘antinode’?
\nAnswer:
\nNode :
\nThe point where the displacement is minimum (zero) of a wave is called Node.<\/p>\n

Antinode :
\nThe point where the displacement is maximum of a wave is called Antinode.<\/p>\n

Question 12.
\nWhat is the distance between a node and an antinode in a stationary wave?
\nAnswer:
\nThe distance between a node and an antinode = \\(\\frac{\\lambda}{\\mathrm{4}}\\)<\/p>\n

Question 13.
\nWhat do you understand by ‘natural frequency’ or ‘normal mode of vibration’?
\nAnswer:
\nNatural frequency :
\nVibrations produced by a body with elastic properties due to application of a constant force are known as natural frequency.
\nEx : For a tuning fork natural frequency depends on elastic nature of the material, the mass distribution and the dimensions of the prongs of the fork.<\/p>\n

Question 14.
\nWhat are harmonics?
\nAnswer:
\nA harmonic is defined as a ‘tone’ of sound having a frequency which is an integral multiple of the fundamental frequency.<\/p>\n

Question 15.
\nA string is stretched between two rigid supports. What frequencies of vibration are possible in such a string?
\nAnswer:
\nThe fundamental frequency of vibration and their harmonics are possible if a string is stretched between two rigid supports. If T is the natural frequency of vibration of the string, then possible their harmonics are 2f, 3f, 4f so on.<\/p>\n

Question 16.
\nThe air column in a long tube, closed at one end, is set in vibration. What harmonics are possible in the vibrating air column?
\nAnswer:
\nIf the fundamental frequency of the air column is denoted by f, then the frequencies at which the second, third, fourth and later modes occur are 3f, 5f, 7f …………… (2n – 1) f. A closed pipe will support only odd Har-monics.<\/p>\n

\"TS<\/p>\n

Question 17.
\nIf the air column in a tube, open at both ends, is set in vibration; what harmonics are possible?
\nAnswer:
\nIf the tube is open at both the ends is set in vibration, the frequencies of the harmonics present in an open pipe are integral multiples of fundamental frequency of the air column. Let f is fundamental frequency then possible harmonics are f, 2f, 3f…. etc.<\/p>\n

Question 18.
\nWhat are ‘beats’?
\nAnswer:
\nBeats :
\nWhen two sounds of nearly equal frequency are superposed, they will create a waxing and warning intensity of sounds. This affect is called “beats”. Beats are produced due to interference of sound waves.
\nBeat frequency \u03c5beat<\/sub> = \u03c51<\/sub> – \u03c52<\/sub><\/p>\n

Question 19.
\nWrite down an expression for beat frequency and explain the terms therein.
\nAnswer:
\nBeat frequency (\u03c5beat<\/sub>) = \u03c51<\/sub> – \u03c52<\/sub>
\nWhere \u03c51<\/sub> and \u03c52<\/sub> are the frequencies is of the two sound waves.<\/p>\n

Question 20.
\nWhat is ‘Doppler effect’? Give an example.
\nAnswer:
\nThe apparent change in the frequency of source of sound due to relative motion between the source and observer is known as doppler’s effect.
\nEx : The whistle of an approaching train appears to have high pitch. When the train is moving away pitch of its whistle decreases.<\/p>\n

Question 21.
\nWrite down an expression for the observed frequency when both source and observer are moving relative to each other in the same direction.
\nAnswer:
\nWhen source and observer are moving in the same direction equation for observed
\n(or) apparent frequency \u03c5 = \u03c50<\/sub> (\\(\\frac{v+v_{0}}{v+v_{s}}\\))<\/p>\n

Short Answer Questions<\/span><\/p>\n

Question 1.
\nWhat are transverse waves? Give illustrative examples of such waves.
\nAnswer:
\nTransverse Waves :
\nIn these waves, the particles of the medium vibrate perpendicular to the direction of propagation of the wave.<\/p>\n

These waves can propagate through solids and liquids.<\/p>\n

Let a rope or string fixed at one end. At the other end continuous periodic up and down jerks are given by a external agency then transverse waves are produced.
\nExample:
\nVibrations in strings, ripples on water surface and electromagnetic waves.<\/p>\n

\"TS<\/p>\n

Question 2.
\nWhat are longitudinal waves? Give illustrative examples of such waves.
\nAnswer:
\nLongitudinal waves :
\nIn these waves particles of the medium vibrate parallel to the direction of propagation of the wave.<\/p>\n