Physical Laboratory ManualHarvard University Press, 1914 - 128 pages |
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abscissae accurate adjusted alternating current ammeter angle angular angular velocity apparatus axis body bridge calculated candle power cell centigram centimeter circuit coil correction crane deflection density determine diffraction grating direction disk distance efficiency curve electrical electrodes electromotive force expressed eyepiece focal length following experiment fork formula friction galvanometer give grams heat horizontal inertia instrument Introduction to Experiments Introductory Remarks lamp lens lenses light load lower end machine magnetic magnetometer main scale means measured meter method moment of inertia monochord necessary object observations obtained ordinates output percentage error photometer pitch numbers plotted pointer position potentiometer pressure prism Procedure pulley R₁ ratio Read Introduction Record resistance resonance tube rotation shown in Fig solution specimen spectra spectrometer spectrum speed spring balance telescope temperature theoretical mechanical advantage torque velocity of sound vernier vertical vibration voltage voltmeter wave length weight Wheatstone bridge wire zero
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Page 81 - It may also be defined as the sine of the angle of incidence divided by the sine of the angle of refraction, as light passes from air into the substance.
Page 57 - Very accurate readings of these temperatures and times are difficult to make and are not necessary. It will be found that the time occupied by 100 revolutions of the spindle diminishes as the temperature rises ; this effect is due to the diminution of the viscosity...
Page 81 - In this way measure all three angles of the prism. turned past the telescope. 38. INDEX OF REFRACTION. When a ray of light passes from a rare to a denser medium it is bent toward the perpendicular to the surface. For the same substances and the same colored light, the sine of the angle of incidence divided by the sine of the angle of refraction is a constant. It is called the index of refraction, and is usually denoted by the letter n. The index of refraction of light passing from air to glass may...
Page 58 - Jouler was in action, the difference (0 2 — #j) between the final and initial temperatures of the water could be used in the calculation without any correction. The correction necessary to allow for the loss of heat in the actual case is ascertained in the following manner. From the observations taken while the Jouler was in action a curve is plotted (the abscissa denoting time, and the ordinate temperature), showing how the temperature increased with the time.
Page 56 - If the string be passed through this eye, it will always turn the cradle so that the string runs fairly over the pulley. In order to prevent the mass M from being wound up over the pulley, an eye is fixed to the steel rod, and the string supporting M passes through this eye. With these arrangements it is impossible, even with...
Page 57 - It will be found that the time occupied by 100 revolutions of the spindle diminishes as the temperature rises ; this effect is due to the diminution of the viscosity of the oil between the cones, consequent upon the rise of temperature. After about 1000 revolutions have been made by the spindle the motion is stopped, and the highest temperature shown by the thermometer is carefully read. The index of the counting wheel is also observed, and from this reading and the number of complete revolutions...
Page 56 - After the counter has been read and the temperature (0i) of the water has been carefully observed and recorded, the operator X turns the hand-wheel fast enough to raise the mass M so far that the string supporting M is tangential to the edge of the disk. If the string be not tangential the moment of its tension about the axis of revolution is seriously diminished. The observer Y stirs the water and notes the temperature at each...
Page 56 - A thermometer is hung from a support so that it passes through the central aperture in the disc, and almost touches the bottom of the inner cone. The thermometer should also pass through the hole in the stirrer. The string supporting M should be of such a length, that when as much as possible has been unwound from the disc, M is not quite in contact with the floor. Before putting the cones together the rubbing surfaces must be carefully cleaned, and then four or five drops of oil must be put between...
Page 56 - The cones, cleaned and oiled, are weighed together with the stirrer. The inner cone is then filled up to about 1 cm. from its top with water 2° or 3° below the temperature of the room, and the system is again weighed. The Jouler is now put into working order, one observer X taking his place at the hand-wheel, and a second observer Y at the Jouler. By working the Jouler, the water is now warmed until its temperature is as nearly as possible equal to that of the room. After the...
Page 59 - Calculation of the heat produced. Let W grams be the mass of the water, and w grams the mass of the cones and stirrer. The specific heat of the metal may be taken as .095, and thus the system of cones, stirrer and water is thermally equivalent to (W + .095 w) grams of water. If the thermometer have a large bulb it is necessary to take account of its water equivalent. The water equivalent is found by heating the thermometer and plunging it while hot into a small vessel of thin copper containing a...