B.Sc. Part-1 Physics Practical Book Honours and Subsidiary Paper
B.Sc. Part-1 Physics Practical Book Honours and Subsidiary Paper. B.Sc. part-1 physics Viva-Voce questions and answers. Honours first year physics practical experiments and viva-voce.
Aim of the Experiment :
(i) A pair of electrically maintained tuning forks of same frequency (or one electrically maintained tuning fork, a non-discharge-tube and a Rumkorft's induction coil).
(ii) A battery of cells.
(iii) A plug key.
(iv) A large and shallow rectangular porcelain trough (ripple tank), ex- perimental liquid (aniline or water).
(v) A porcelain scale with MM graduations.
(vi) A thermometer and
(vii) A stroboscopic diso arrangement.
Theory:
The method is based upon generating ripples on water surface and measuring the wavelength 'λ' of these ripples. The velocity v of propagation of such ripples is given by.
Where,
g = acceleration due to gravity
p = density of water
T = surface tension of water.
Putting, v = nλ
Where n is the frequency.
Procedure:
The electrically maintained tuning fork arrangement is shown in figures respectively.
(i) The experimental liquid is taken in a neat and clean rectangular porcelain trough to such a depth that the lower edge of the dipper (P) just touches the liquid surface.
(ii) Above trough, an electrically maintained tuning fork F of large rongs are horizontal and vibrate in frequency is mounted such that its p vertical plane.
(iii) By setting the fork vibration, the pointer (dipper) moves in and out of the liquid. This motion of pointer produces ripples in liquid.
(iv) To find wavelength of ripples, liquid surface is illuminated by neon discharge tube. Every time when tuning fork circuit is made, discharge passes through the tube and thus liquid surface is illuminated. (Tunning fork circuit is completed through the primary of an induction coil, to the secondary of which a neon discharge tube is connected.
Another way to view these ripples is stroboscopic method in which another fork of exactly same frequency is included in the same circuit as shown in figure. Since, the frequency of ripples and that of the fork are the same, ripples appear to be stationary due to persistance of vision.
(v) To photograph ripples, a lamp with make and break arrangement is used so that frequency of light is that of the tunning fork.
(vi) To find wavelength, the maximum number of waves are counted in a help of a scale placed at the bottom of through.
(vii) knowing λ,n and p, the value of surface tension T can be calculated.
Observation:
Temp. Of water in the through = 22.5°C frequency, n = 100 Hz, p ( water = 1000 kg/m3 and g = 9.8 m/s.
Measurement of wavelength λ of ripples :
Calculations :
From the relation,
Source of errors and precautions:
(i) The deeper P should just touch the liquid surface.
(ii) There should be no mechanical jerk other than vibrations due to fork.
(iii) The trough must be clean and soft wax.
(iv) The wavelength can be measured accurately only when crest are well defined.
(v) Temperature of the liquid changes due to vibrations and therefore it should be recorded at various times during the course of the experiment.
(vi) Liquid should be available in sufficient quantity.
Ans. the waves in liquid for which wavelength is less than critical wave. length are called ripples.
2. What are waves ?
Ans. Disturbances in liquid for which wavelength is greater than critical value are called waves.
3. How the ripples propagate ?
Ans. Ripples propagate due to surface tension.
4. For which liquid is this method most suitable ?
Ans. This method is most suitable for those liquid whose surface is reflecting (such as mercury).
5. What is stroboscopic method ?
Ans. This is another method for finding wavelength of ripples, in which two forks of exactly same frequency is included in the circuit. Since, the frequency of ripples and that of fork are the same, ripples appear to be stationary due to persistence of vision. In this method, A parallel beam of strong light proceeding in planes perpendicular to the plane of vibration of the prongs, are reflected by the ripple-covered surface of the liquid and are allowed to pass obliquely up- ward through the transparent scale and the wire. As the wire and the scale are in the same plane, the maginfication of their images as seen by the telescope will be the same. An observer looking through the telescope, sces the image of the wire not straight but a wavelike form of the ripples, for the light is proceeding in planes parallel to the crest or troughs of the real stationary ripples. By assuming the wavelength of the shadow of wire is equal to the wavelength of real ripples, we can find the wavelength of ripples.
Keywords :
Honours first year physics practical book.
Honours part 1 physics practical book download.
B.Sc. part 1 physics practical book online read.
B.Sc. part 1 physics practical.
B.Sc. physics practical.
Determination of surface tension of liquid (water) by the method of Ripples.
Apparatus Required:(i) A pair of electrically maintained tuning forks of same frequency (or one electrically maintained tuning fork, a non-discharge-tube and a Rumkorft's induction coil).
(ii) A battery of cells.
(iii) A plug key.
(iv) A large and shallow rectangular porcelain trough (ripple tank), ex- perimental liquid (aniline or water).
(v) A porcelain scale with MM graduations.
(vi) A thermometer and
(vii) A stroboscopic diso arrangement.
Theory:
The method is based upon generating ripples on water surface and measuring the wavelength 'λ' of these ripples. The velocity v of propagation of such ripples is given by.
g = acceleration due to gravity
p = density of water
T = surface tension of water.
Putting, v = nλ
Where n is the frequency.
The electrically maintained tuning fork arrangement is shown in figures respectively.
(i) The experimental liquid is taken in a neat and clean rectangular porcelain trough to such a depth that the lower edge of the dipper (P) just touches the liquid surface.
(ii) Above trough, an electrically maintained tuning fork F of large rongs are horizontal and vibrate in frequency is mounted such that its p vertical plane.
(iv) To find wavelength of ripples, liquid surface is illuminated by neon discharge tube. Every time when tuning fork circuit is made, discharge passes through the tube and thus liquid surface is illuminated. (Tunning fork circuit is completed through the primary of an induction coil, to the secondary of which a neon discharge tube is connected.
(v) To photograph ripples, a lamp with make and break arrangement is used so that frequency of light is that of the tunning fork.
(vi) To find wavelength, the maximum number of waves are counted in a help of a scale placed at the bottom of through.
(vii) knowing λ,n and p, the value of surface tension T can be calculated.
Observation:
Temp. Of water in the through = 22.5°C frequency, n = 100 Hz, p ( water = 1000 kg/m3 and g = 9.8 m/s.
Measurement of wavelength λ of ripples :
From the relation,
(i) The deeper P should just touch the liquid surface.
(ii) There should be no mechanical jerk other than vibrations due to fork.
(iii) The trough must be clean and soft wax.
(iv) The wavelength can be measured accurately only when crest are well defined.
(v) Temperature of the liquid changes due to vibrations and therefore it should be recorded at various times during the course of the experiment.
(vi) Liquid should be available in sufficient quantity.
B.Sc. Part-1 Physics Viva-Voce
1. What are the ripples ?Ans. the waves in liquid for which wavelength is less than critical wave. length are called ripples.
2. What are waves ?
Ans. Disturbances in liquid for which wavelength is greater than critical value are called waves.
3. How the ripples propagate ?
Ans. Ripples propagate due to surface tension.
4. For which liquid is this method most suitable ?
Ans. This method is most suitable for those liquid whose surface is reflecting (such as mercury).
5. What is stroboscopic method ?
Ans. This is another method for finding wavelength of ripples, in which two forks of exactly same frequency is included in the circuit. Since, the frequency of ripples and that of fork are the same, ripples appear to be stationary due to persistence of vision. In this method, A parallel beam of strong light proceeding in planes perpendicular to the plane of vibration of the prongs, are reflected by the ripple-covered surface of the liquid and are allowed to pass obliquely up- ward through the transparent scale and the wire. As the wire and the scale are in the same plane, the maginfication of their images as seen by the telescope will be the same. An observer looking through the telescope, sces the image of the wire not straight but a wavelike form of the ripples, for the light is proceeding in planes parallel to the crest or troughs of the real stationary ripples. By assuming the wavelength of the shadow of wire is equal to the wavelength of real ripples, we can find the wavelength of ripples.
Keywords :
Honours first year physics practical book.
Honours part 1 physics practical book download.
B.Sc. part 1 physics practical book online read.
B.Sc. part 1 physics practical.
B.Sc. physics practical.
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