THE SCREW GAUGE. AIM: To learn to use a Screw Gauge and hence use it to find the dimensions of various regular materials given.

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Scarlett Whitehead
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1 EXPERIMENT NO: DATE: / /0 THE SCREW GAUGE AIM: To learn to use a Screw Gauge and hence use it to find the dimensions of various regular materials given. APPARUTUS:Given a Screw Gauge, cylindrical glass rod and a cylindrical wire. THEORY:The Least Count of an instrument is the smallest possible measurement accurately possible using that instrument.this definition suits any instrument that one may use to measure any physical quantity. The lower the value of the least count, the smaller the readings one can take using it. The least count of the commonly used meter scale is mm. Usually the least count of a screw gauge is 0.0mm. This means that using a SG, we can measure very small length dimensions like the diameter of a small wire. The formu la fo r finding the least count of any instrument that has two scales one running over the other is given by Smallest Value of Main Scale LLeast CCount (LC) = Total number of divisions in the Vernier Scale In the case of the Screw Gaugeapplying the above formula, we get PROCEDURE: LC of SSSSSSSSSS GGGGGGGGGG = mm 00 div = 0.0mm. The first step is to find the zero error of the instrument. The zero error of the instrument will either be zero, negative or positive. To find the zero error, tighten the screws to close the gap. Hold the U shaped metallic frame with you left hand and turn the screws using your right hand. Always make sure you hold the screw at the ratchet (the black piece) only while turning the screws. When the screw is completely closed, a click sound is heard at the ratchet end. Turn the ratchet further, VERY GENTLY, to hear more clicks. w, when the screw gauge is closed, look at the reading. a) If the zero of the circular scale is in line with the main scale, zero error = 0 b) If the zero ofthe circular scale is above the zero of the main scale, zero error = negative (eg: 7 divisions). c) If the zero of the circular scale is below the zero of the main scale, zero error = positive (eg: + divisions). te this down above the tabular column.. Keep the material to be measured in the U shaped metallic frame and tighten the screws to close the gap. Always make sure you hold the screw at the ratchet (the black piece) only while turning the screws.when the screw is completely closed, a click sound is heard at the ratchet end. Turn the ratchet further, VERY GENTLY, to hear more clicks.. Look for the reading on the main scale (also known as Head Scale or Pitch Scale). This is the Main Scale Reading (MSR). te this down in the table with appropriate units. 4. w, look for the division on the Circular Scale that coincides with the main scale. This would be your Circular Scale Reading (CSR). Tabulate this reading (it has no unit as it is just a division). 5. Find the Tota; Reading (TR) in each case using the formula... TTTT = MMMMMM + [(CCCCCC ZZZZ) LLLL].te that this equation is sign sensitive and so the negative zero error will get added up in the total result and the positive zero error will get subtracted. TABLES (left side): Zero Error of Screw gauge = MSR TR = MSR + (VSR ZE) CSR [mm] LC[mm] Diameter of the Glass Tube (D) Diameter of the Wire (d ) Average Value of Diameter of the glass tube D = mm Average Value of Diameter of the wire d = mm CALCULATIONS (left side): The Radius of the given cylindrical glass rod is given by the equation RR = DD mm = mm The Radius of the given cylindrical wire is given by the equation rr = dd mm = mm RESULT (bottom of page on the right side): The Radius of the given cylindrical glass rod was found to be mm The Radius of the given cylindrical wire was found to be mm

2 EXPERIMENT NO: DATE: / / 0 VERNIER CALLIPERS AIM: To learn to use the Vernier Callipers (VC) and hence use it to find the dimensions of given regular materials. APPARUTUS:Given a Vernier Callipers (VC), a hollow cylinder THEORY: PROCEDURE: value of one main scale division Least Count of Veeeeeeeeeeee CCCCCCCCCCCCCCCCCC = number of divisions in the vernier scale = mm 0 div = 0.mm. Identify the main scale and the Vernier scale of the vernier callipers.. Find the value of one main scale division and the number of divisions in the Vernier scale.. Remember to use the jaws on the upper side of the VC only to measure inner diameter of tubes or other regular shapes; for all other external measurements, use the lower jaws. 4. Keep the material to be measured between the jaws of the VC and lock the jaws completely to the object. 5. Look for the reading on the main scale that comes just before the zero marking on the Vernier scale. Th is is the Main Scale Reading (MSR). te this down in the table with appropriate units. 6. w, look for the first division on the Vernier scale that coincides perfectly with any division on the main scale. This would be your Vernier Scale Reading (VSR). Tabulate this reading too (it has no unit as it is just a division). 7. The total Reading (TR) is given by TR = MSR + (VSR LC). 8. Repeat the experiment t imes and find the average value of TR. MSR VSR Outer Diameter of the Hollow Cylinder (R) Inner Diameter o f the Ho llo w Cylinder (r) Height (or Length) of the Hollow Cylinder (h) CALCULATIONS: The Volume of the given Hollow cylinder is given by the formula TTTT = MMMMMM + (VVVVVV) LLLL Average Value of Outer Diameter R = cm Average Value of Inner Diameter r = cm Average Value of Height h= cm VV = ππrr h ππrr h = ππh(rr rr ) = ccmm RESULT: The Volume of the given Hollow cylinder was found to be ccmm

3 EXP ERIMEN T NO: DATE: / /0 THE SIMPLE PENDULUM AIM: To find the value of acceleration due to gravity using a simple pendulum. APPARATUS:Given a bob attached to a mass less string, a meter scale, a stop clock and a stand FORMULA: T = π L g PROCEDURE: T = 4π L g g = 4π L T g = 4π 4π g = S S. Set the Simple pendulum for a convenient length (say 40 cm) and calculate the time that it takes to make 0 oscillations (0T, where T is the time period).. Care must be taken to ensure that the angle of oscillation from the mean position is as small as possible. Care must also be taken in order to ensure that no initial velocity is given to the pendulum. It must be allo wed to fall freely from the displaced position.. After the time reading for 0T is taken, do not stop the oscillation. 4. te down the value of time then, reset the watch and as the pendulum continues to oscillate, take the value for 0 T once more. te this down too in the tabular column. 5. w, change the value of length (to say 60 cm) and repeat the whole experiment for 4 more values of length.in each of the tabulated values, find T and T and note it in the tabular column. 6. Plot a graph of L versus T (L on the x axis and T on the y axis). It is expected to be a straight line. 7. All the points plotted may not fall on a straight line so draw a LINE OF BEST FIT. (The line of best fit may even be drawn in a manner that none of the points plotted falls exactly on the line itself. This would still be the correct way of drawing the graph). 8. On the line of best fit, choose any two new points (xx,yy ) and (xx,yy ) and hence find the slope of the line. Using the equation SS = y x = y y = 4π x x g 9. Find the value of acceleration due to gravity from the equation given above g = 4π S L T [s] T [s] AverageT [s] TT [s ] RESULT:The value of acceleration due to gravity was found to be m/s

4 EXPERIMENT NO:4 DATE: / / 0 FINDING VOLUME OF REGULAR OBJECTS AIM: To find the volume of a given solid object using liquid displacement method and then to confirm the values using mathematical formula and dimensions calculated using Vernier Callipers (VC). APPARATUS:Given a spherical bob, a cylindrical metal object, measuring jar with water, string and vernier callipers. PROCEDURE:. te down the least count of the measuring cylinder (LC) Fill the measuring jar to a comfortable level and note this value as the initial reading of volume in the water (R i ). Take care to ensure that readings on the measuring cylinder is taken by keeping your eye horizontally in line with the reading and not at an angle to avoid parallax errors.. Tie the given sphere with a string. Take care to ensure that the string is long enough so that the objects will completely immerse in the water in the measuring jar.. Dip the bob such that it just immerses completely inside the water. te the reading of the measuring jar now. This will be the final reading (R f ).The volume of the Bob will be the difference between R f and R i. 4. Repeat the steps and for the cylindrical object and note down the values separately. 5. te the Least Count of the given VC. Use the VC to find the value of (i) diameter of the sphere (ii) diameter of the cylinder and (iii) the length of the cylinder and note all these values down. 6. In each case, take readings and the mean of these readings to get a more accurate result. 7. Make the mathematical calculation for Volume for each of these objects using the concerned formula for volume of sphere and volume of cylinder. CALCULATIONS: Least count of the VC = cm Least count of the measuring jar = cc. SPHERICAL BOB Initial Reading on the measuring jar R i = cc Final Reading on the measuring jar R f = cc Volume of Bob = RR ff RR ii = cc Average Diameter of the Bob using VC = d = cm Radius of the Bob = rr = dd = cm Volume of the Bob = 44 ππrr = cc. CYLINDRICAL METAL OBJ ECT Initial Reading on the measuring jar R i = cc Final Reading on the measuring jar R f = cc Volume of Cylinder = RR ff RR ii = cc Average Diameter of the cylinder using VC = D = cm Radius of the cylinder = RR = DD = cm Average Length of the cylinder using VC = L = cm Volume of the Cylinder = ππrr LL = cc M SR VSR Diameter of Sphere (d) TTTT = MSR + (VSR LC) M SR VSR Diameter of Cylinder (D) Length of Cylinder (L) TTTT = MSR + (VSR LC) RESULT:. The volume of the Bob using Measuring jar is : cc. The volume of the Bob using Vernier callipers is : cc. The volume of the Cylinder using Measuring jar is : cc 4. The volume of the Cylinder using Vernier Callipers is : cc

5 EXPERIMENT NO:5 DATE: / /0 DENSITY OF WOOD Aim: To find the Density of the given Wooden Block Apparatus: Given a Vernier Callipers, digita l weighing pan and a block of wood(cuboid) Formula : DDDDDDDDDDDDDD = MMMMMMMM VVVVVVVVVVVV DD = MM VV Volume of a Cubiod = length breadth height VV = ll bb h Procedure:. Find and record the mass of the block of wood using the digital weighing pan.. Find the volume of the given wooden block by finding the length, breadth and height of the block using the given vernier callipers.. Use the formula for density to find the density of the wooded block. Make sure all the units are in the SI system while finding the density. Calculations: Length of the wooden block ll = cccc = mm Breadth of the wooden block bb = cccc = mm Height of the wooden block h = cccc = mm Volume of the Wooden Block VV = ll bb h = mm Mass of the given wooden block MM = gg = kkkk The density of the given wooden block is MSR VSR Length of the Wooden Block (l) Breadth of the Wooden Block (b) Height of the Wooden Block (h) TR = MSR + (VSR LC) [c m] DD = MM VV = kkkk/mm Result: The density of the given wooden block is found to be kkkk/mm

6 EXPERIMENT NO:6 DATE: / /0 REFLECTION OF LIGHT Aim: To verify the laws of reflection Apparatus: A drawing board, pins, a plane mirror, wooden block for support. Sheet of paper Procedure:. Fix the sheet of paper firmly on the drawing board. Draw a straight line MM on the paper to represent the position of the plane mirror. Draw the normal (perpendicular line) ON from the centre point O on the straight line MM 4. Draw a straight line AO at an angle 0 to the left side of the normal ON. N 5. Place the mirror in vertical position with the help of a wooden block on the line MM 6. Fix two common pins B and C on the line AO on the. 7. Look at the mirror from the right side of the normal in such a manner that the reflections of pins B and C are aligned. 8. w fix two pin D and E on the right side such that these two are aligned with the reflection of B and C. 9. Take care to ensure that the reflection of B and C and the pins D and E are on a straight line. 0. w take the pins out and join D and E to the point O with a pencil.. Measure angle AON and angle NOE with a protractor. They will be the same.. Repeat the experiment for an angle of 60. Result: The laws of Reflection of Light were verified. te: te the angles in the paper itself and attach it in the record book

7 EXPERIMENT NO: 7 DATE: / / 0 VOLUME OF IRREGULAR OBJECT LIGHTER THAN WATER Aim: To determine the volume of an irregular shape object lighter than water by displacement method Apparatus: Given irregular object (a piece of cork which does not sink in water), a measuring cylinder and a heavy object to be used as sinker. Theory: An object when completely immersed in a liquid displaces an equal volume of the liquid. Initial volume of water in the measuring cylinder = V ml Volume of water with sinker immersed = V ml Volume of water with sinker and the object both immersed = V ml Volume of water displaced by the object when completely immersed = (V V ) ml Therefore volume of the object V = (V V ) ml Procedure. te the least count of the given measuring cylinder with the proper unit.. Fill little water in the measuring cylinder and record its level as V ml. Use a string to immerse the given sinker, a heavy object which sinks in water and record the water level in the measuring cylinder as V ml 4. Tie the object to the sinker and immerse it completely in water. Then record the water level in the measuring cylinder as V ml. 5. Record your observations for V, V, and V in the given observation table and calculate v, the volume of the object. 6. Repeat the procedure by changing the initial level of water in the measuring cylinder (V ) for at least two more set of observations. 7. Therefore volume of the object V = (V V ) ml Observations: Least count of the measuring cylinder = ml V [ml] V [ml] V [ml] V = (V V ) [ml] Result: Volume of the given object which does not sink in water, as determined by displacement method, using a sinker is found to be as ml = cm.

THE SCREW GAUGE. AIM: To learn to use a Screw Gauge and hence use it to find the dimensions of various regular materials given.

THE SCREW GAUGE. AIM: To learn to use a Screw Gauge and hence use it to find the dimensions of various regular materials given. EXPERIMENT NO: DATE: / / 0 THE SCREW GAUGE AIM: To learn to use a Screw Gauge and hence use it to find the dimensions of various regular materials given. APPARUTUS: Given a Screw Gauge, cylindrical glass