A MANUAL OF PRACTICAL PHYSICS
1 INTRODUCTORY CONCEPTS 1 1 1 AIM OF THE EXPERIMENT 1 1 2 IMPORTANCE OF LABORATORY WORK 1 1 3 GENERAL INSTRUCTIONS FOR PERFORMING EXPERIMENTS 2 1 4 HOW TO RECORD AN EXPERIMENT IN THE PRACTICAL FILE 2 1 5 ERRORS AND OBSERVATIONS 3 1 6 ACCURACY OF OBSERVATIONS 4 1 7 ACCURACY OF THE RESULT 4 1 8 PERMISSIBLE ERROR IN THE RESULT 4 1 9 HOW TO ESTIMATE THE PERMISSIBLE ERROR IN THE RESULT 5 1 10 ESTIMATING MAXIMUM PERMISSIBLE ERROR 6 1 11 PERCENTAGE ERROR 7 1 12 SIGNIFICANT FIGURES PRECISION OF MEASUREMENT 7 1 13 ROUNDING OFF 7 1 14 LOGARITHMS 8 1 15 HOW TO READ FOUR FIGURE LOGARITHM TABLES 9 1 16 GRAPH 10 1 17 CALCULATIONS OF SLOPE OF A STRAIGHT LINE 11 1 18 INTERNATIONAL SYSTEM OF UNITS S I UNITS 12 1 19 RULES FOR MEASUREMENTS IN THE LABORATORY 12 2 INSTRUMENTS AND ACCESSORIES 13 2 1 SOME INSTRUMENTS FOR MEASUREMENT OF LENGTH 13 2 2 TRAVELLING MICROSCOPE 19 2 3 CATHETOMETER 20 2 4 THE BALANCE 21 2 5 THE OPTICAL BENCH 25 2 6 PARALLAX 26 2 7 THE SPECTROMETER 26 2 8 ADJUSTMENTS OF THE SPECTROMETER 27 2 9 THEORY OF SCHUSTER S METHOD 30 2 10 A SLIDING RHEOSTAT 31 2 11 POWER OF ACCOMMODATION OF THE EYE 32 2 12 VISUAL ANGLE MAGNIFYING POWER OF OPTICAL INSTRUMENTS 32 2 13 ASTRONOMICAL REFRACTING TELESCOPE 33 2 14 REFLECTING TELESCOPE 35 2 15 SIMPLE MICROSCOPE 36 2 16 COMPOUND MICROSCOPE 38 2 17 RESOLVING POWER OF OPTICAL INSTRUMENTS 41 2 18 ELECTRON MICROSCOPE 43 2 19 EYE PIECE OCULARS 43 2 20 HUYGENS EYEPIECE 43 2 21 CARDINAL POINTS OF A HUYGENS EYE PIECE 45 2 22 RAMSDEN EYE PIECE 46 2 23 CARDINAL POINTS OF A RAMSDEN EYE PIECE 47 2 24 GAUSS EYE PIECE 48 2 25 COMPARISON OF EYE PIECES 48 2 26 SPECTRUM 49 2 27 SOURCES OF LIGHT 50 2 28 SODIUM VAPOUR LAMP 51 2 29 MERCURY VAPOUR LAMP 52 2 30 ELECTROMAGNETIC SPECTRUM 53 3 ELASTICITY 55 3 1 ELASTICITY 55 3 2 LOAD 55 3 3 STRESS 55 3 4 STRAIN 56 3 5 HOOKE S LAW 56 3 6 ELASTIC LIMIT 56 3 7 TYPES OF ELASTICITY 56 3 8 YOUNG S MODULUS OR ELASTICITY OF LENGTH 57 3 9 BULK MODULUS OR ELASTICITY OF VOLUME 57 3 10 MODULUS OF RIGIDITY TORSION MODULUS OR ELASTICITY OF SHAPE 58 3 11 AXIAL MODULUS 58 3 12 POISSON S RATIO 59 3 13 RELATION BETWEEN ELASTIC CONSTANT 59 3 14 LIMITING VALUES OF POISSON S RATIO 60 3 15 TWISTING COUPLE ON A CYLINDER 60 3 16 OBJECT BARTON S APPARATUS 62 3 17 BEAM 66 3 18 BENDING OF A BEAM 66 3 19 THEORY OF SIMPLE BENDING 67 3 20 BENDING MOMENT 67 3 21 THE CANTILEVER 69 3 22 BEAM SUPPORTED AT BOTH THE ENDS AND LOADED IN THE MIDDLE 70 3 23 OBJECT YOUNG S MODULUS 71 3 24 OBJECT POISSON S RATIO FOR RUBBER 74 3 25 FLY WHEEL MOMENT OF INERTIA 78 3 26 TORSION TABLE ELASTICITY 81 3 27 OBJECT TO DETERMINE THE RESTORING FORCE PER UNIT EXTENSION OF A SPIRAL SPRING BY STATICAL AND DYNAMICAL METHODS AND ALSO TO DETERMINE THE MASS OF THE SPRING 85 3 28 OBJECT TO STUDY THE OSCILLATIONS OF A RUBBER BAND AND A SPRING 90 3 29 OBJECT TO DETERMINE YOUNG S MODULUS MODULUS OF RIGIDITY AND POISSON S RATIO OF THE MATERIAL OF A GIVEN WIRE BY SEARLE S DYNAMICAL METHOD 93 3 30 OBJECT TO DETERMINE THE VALUE OF THE MODULUS OF RIGIDITY OF THE MATERIAL OF A GIVEN WIRE BY A DYNAMICAL METHOD USING MAXWELL S NEEDLE 99 3 31 OBJECT TO STUDY THE VARIATION OF MOMENT OF INERTIA OF A SYSTEM WITH THE VARIATION IN THE DISTRIBUTION OF MASS AND HENCE TO VERIFY THE THEOREM OF PARALLEL AXES 103 3 32 VIVA VOCE 105 4 ACCELERATION DUE TO GRAVITY 118 4 1 ACCELERATION DUE TO GRAVITY 118 4 2 PERIODIC MOTION 118 4 3 SIMPLE HARMONIC MOTION 118 4 4 ENERGY OF A HARMONIC OSCILLATOR 120 4 5 THE SIMPLE PENDULUM 121 4 6 DRAWBACKS OF A SIMPLE PENDULUM 122 4 7 THE COMPOUND PENDULUM 122 4 8 CENTRE OF OSCILLATION 124 4 9 INTERCHANGEABILITY OF CENTRES OF SUSPENSION AND OSCILLATION 124 4 10 MAXIMUM AND MINIMUM TIME PERIOD OF A COMPOUND PENDULUM 125 4 11 ADVANTAGES OF A COMPOUND PENDULUM 126 4 12 DETERMINATION OF THE VALUE OF G 126 4 13 OBJECT TO DETERMINE THE VALUE OF G AND THE MOMENT OF INERTIA OF A BAR ABOUT C G BY MEANS OF A BAR PENDULUM 126 4 14 TIME PERIOD OF A PENDULUM FOR LARGE AMPLITUDE 131 4 15 OBJECT TO DETERMINE THE VALUE OF ACCELERATION DUE TO GRAVITY AT A PLACE BY MEANS OF KATER S REVERSIBLE PENDULUM 132 4 16 VIVA VOCE 135 5 SURFACE TENSION 140 5 1 SURFACE TENSION 140 5 2 DEFINITION OF SURFACE TENSION 140 5 3 SURFACE ENERGY 141 5 4 MOLECULAR THEORY OF SURFACE TENSION 142 5 5 SHAPE OF LIQUID MENISCUS IN A GLASS TUBE 143 5 6 ANGLE OF CONTACT 143 5 7 EXCESS OF PRESSURE ON CURVED SURFACE OF LIQUID 144 5 8 CAPILLARITY RISE OF LIQUID 145 5 9 OBJECT TO FIND THE SURFACE TENSION OF A LIQUID WATER BY THE METHOD OF CAPILLARY RISE 147 5 10 OBJECT TO DETERMINE THE SURFACE TENSION OF A LIQUID WATER BY JAEGER S METHOD 151 5 11 VIVA VOCE 155 6 VISCOSITY 160 6 1 IDEAL LIQUID 160 6 2 STREAM LINED FLOW 160 6 3 PRINCIPLE OF CONTINUITY 160 6 4 ENERGY OF A FLOWING LIQUID 161 6 5 BERNOULLI S THEOREM 162 6 6 VELOCITY OF EFFLUX 162 6 7 VISCOSITY 163 6 8 CRITICAL VELOCITY 164 6 9 VELOCITY GRADIENT AND COEFFICIENT OF VISCOSITY 165 6 10 EFFECT OF TEMPERATURE ON VISCOSITY 166 6 11 POISEUILLE S FORMULA 166 6 12 STOKE S LAW FOR VISCOUS DRAG ON MOVING BODIES 168 6 13 EFFECT OF VARIOUS FACTORS ON VISCOSITY OF FLUIDS 169 6 14 OBJECT DETERMINATION OF THE VISCOSITY OF WATER BY METHOD OF CAPILLARY FLOW 169 6 15 ROTATING CYLINDER METHOD 172 6 16 OBJECT TO DETERMINE THE COEFFICIENT OF VISCOSITY OF WATER BY ROTATING CYLINDER METHOD 175 6 17 VIVA VOCE 179 7 SOUND 182 7 1 SPEED OF TRANSVERSE WAVE IN STRETCHED STRING 182 7 2 VIBRATIONS OF STRETCHED STRING 182 7 3 FUNDAMENTAL AND OVERTONES OF A STRING 183 7 4 SONOMETER 184 7 5 OBJECT TO DETERMINE THE FREQUENCY OF A C MAINS BY USING A SONOMETER AND A HORSE SHOE MAGNET 185 7 6 OBJECT TO DETERMINE THE FREQUENCY OF A C MAINS OR OF AN ELECTRIC VIBRATOR BY MELDE S EXPERIMENT USING 188 7 7 VIVA VOCE 190 8 THE MECHANICAL EQUIVALENT OF HEAT 194 8 1 DESCRIPTION OF THE CALLENDER AND BARNES CALORIMETER 194 8 2 OBJECT TO DETERMINE THE MECHANICAL EQUIVALENT OF HEAT J BY THE CALLENDER AND BARNES METHOD 195 8 3 VIVA VOCE 197 9 THERMOELECTRIC EFFECT 199 9 1 THERMOELECTRIC EFFECT 199 9 2 ORIGIN OF THERMO E M F 199 9 3 MAGNITUDE AND DIRECTION OF THERMO E M F 200 9 4 PELTIER EFFECT 201 9 5 PELTIER COEFFICIENT 202 9 6 THOMSON S EFFECT 202 9 7 THOMSON COEFFICIENT 203 9 8 THERMOPILE 203 9 9 OBJECT TO CALIBRATE A THERMOCOUPLE AND TO FIND OUT THE MELTING POINT OF NAPHTHALENE 205 9 10 VIVA VOCE 207 10 REFRACTION AND DISPERSION OF LIGHT 212 10 1 REFRACTION OF LIGHT 212 10 2 REFRACTION THROUGH A PRISM 214 10 3 MINIMUM DEVIATION 214 10 4 FORMULA FOR THE REFRACTIVE INDEX OF THE PRISM 215 10 5 DEVIATION PRODUCED BY A THIN PRISM 215 10 6 CRITICAL ANGLE AND TOTAL INTERNAL REFLECTION 216 10 7 DISPERSION OF LIGHT BY A PRISM 216 10 8 DISPERSIVE POWER OF AN OPTICAL MEDIUM 217 10 9 PRODUCTION OF PURE SPECTRUM 218 10 10 OBJECT DETERMINATION OF THE DISPERSIVE POWER OF A PRISM 219 10 11 VIVA VOCE 222 11 INTERFERENCE OF LIGHT 226 11 1 INTERFERENCE 226 11 2 CONDITION OF INTERFERENCE OF LIGHT 226 11 3 COHERENT SOURCES 226 11 4 PHASE DIFFERENCE AND PATH DIFFERENCE 227 11 6 THEORY OF INTERFERENCE FRINGES 230 11 7 STOKE S TREATMENT TO EXPLAIN CHANGE OF PHASE ON REFLECTION 231 11 8 INTERFERENCE IN THIN FILMS 232 11 9 INTERFERENCE DUE TO REFLECTED LIGHT THIN FILMS 232 11 10 INTERFERENCE DUE TO TRANSMITTED LIGHT THIN FILMS 234 11 11 COLOURS OF THIN FILMS 235 11 12 NON REFLECTING FILMS 235 11 13 NECESSITY OF A BROAD SOURCE 236 11 14 FRINGES PRODUCED BY A WEDGE SHAPED THIN FILM 237 11 15 TESTING THE PLANENESS OF SURFACES 238 11 16 NEWTON S RINGS 239 11 17 NEWTON S RINGS BY TRANSMITTED LIGHT 241 11 18 DETERMINATION OF THE WAVELENGTH OF SODIUM LIGHT USING NEWTON S RINGS 242 11 19 REFRACTIVE INDEX OF A LIQUID USING NEWTON S RINGS 242 11 20 NEWTON S RINGS WITH BRIGHT CENTRE DUE TO REFLECTED LIGHT 244 11 21 NEWTON S RINGS WITH WHITE LIGHT 244 11 22 INTERFERENCE FILTER 244 11 23 OBJECT MEASUREMENT OF WAVE LENGTH OF SODIUM LIGHT BY NEWTON S RINGS 245 11 24 VIVA VOCE 248 12 DIFFRACTION OF LIGHT 252 12 1 DIFFRACTION 252 12 2 CLASSIFICATION OF DIFFRACTION 252 12 3 FRESNEL S CLASS OF DIFFRACTION 252 12 4 FRAUNHOFFER CLASS OF DIFFRACTION 253