INTRODUCTION TO PHYSICS PRACTICALS AND PRACTICAL APPARATUS
PHYSICS is the branch of natural science concerned with the nature and properties of matter and energy (forces acting on them) which is responsible for its pattern of motion and behavior through space and time. OR simply put that it is the study of matter, energy, and the interaction between them. The word Physics is a Greek word and it simply means KNOWLEDGE OF NATURE.

STUDY OF MATTER INVOLVES
 1.  Learning about their shapes and sizes. (MEASURMENTS)
 2.  Learning about their movement and direction. (MOTION and VECTOR)
 3.  Learning about their chemical properties. (ATOMIC PROPERTIES)
 4.  Learning about their interactions with other matters (FORCES).
The subject matter of physics includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms.
PHYSICS PRACTICAL: this can be defined as experimental approach in the study of nature and properties of matter and energy, using various improvised and standard equipment to quantify and measure accurately the object under study. Therefore, physics experiments starts with learning all about existing equipments available which enhances the study of physics.

PHYSICS LABORATORY EQUIPMENTS
 1.  Meter Rule/Stick: this is a one meter long ruler that helps us measure the length and breadth of an object in most cases a regular shaped object. A metric ruler is used to measure the length, height and width of an object or the distance between two points, objects or places. Depending on the length of the metric ruler, it can be divided into millimeters, centimeters, decimeters or meters. The accuracy of meter rule is 0.1cm or 1mm, therefore, when you measure an object and the final point falls not exactly on a specific mark rather in between two marks, one is usually tempted to approximate thereby leaving us with some errors. And also it means that meter rule cannot be used to measure an object whose length is less than 1mm. You will see how vernier caliper solves these errors due to approximation uniquely, and micrometer solves it even more accurately. But the problem with these other better accuracy instruments is that the distance they can measure is very limited.

METER RULE/STICK

It is also observed that students of practical physics always seek for meter rule that its graduation is complete that is starting from mark 0 to 100 before they are comfortable using it. The ruler in fig. 1.; is incomplete and in as much as the distance you want to measure is less than 21cm, the ruler can be used accurately. For example, if you use the shortened meter stick as in fig. 1.; to measure an object and the value is from mark 80cm to mark 97cm, all you need to do is to subtract 80 from 97 and the object measured is 17cm.

 2.  Inside Caliper: this instrument is used in the measurement of internal diameters of cylindrical hollow objects, like cups, pipes etc. In the early stage of its invention, it looks exactly like in figure A., and as it is it does not have its own scale but must be used in conjunction with a ruler/meter stick to determine its value. It progressed to graduated version, dial type, analog and finally digital.

INSIDE CALIPER



 3.  Outside Caliper: this instrument is used in the measurement of external diameters of cylindrical hollow objects, like cups, pipes etc. In the early stage of its invention, it looks exactly like in figure A., and as it is it does not have its own scale but must be used in conjunction with a ruler/meter stick to determine its value. It progressed to graduated version, dial type, analog and finally digital.

OUTSIDE CALIPER



 4.  VERNIER CALIPER: this instrument helps us measure shorter length and breadth of an object that ruler cannot measure accurately. This instrument is just like a ruler except that it is 10 times more accurate than meter rule. Its accuracy is about 0.01cm. Reading this instrument is complex and requires special topic and practical to understand its use. Diagram of Vernier calipers. The labeled parts are:
 1. Outside caliper jaws: used to measure external diameter or width of an object
 2. Inside caliper jaws: used to measure internal diameter of an object
 3. Depth probe/rod: used to measure depths of an object or a hole
 4. Main scale (Metric): scale marked every mm
 5. Main scale (Imperial): scale marked in inches and fractions
 6. Vernier scale (Metric) gives interpolated measurements to 0.1 mm or better
 7. Vernier scale (Imperial) gives interpolated measurements in fractions of an inch
 8. Fine adjust/Retainer: used to block movable part to allow the easy transferring of a measurement

VERNIER CALIPER


VERNIER CALIPER


READING VERNIER CALIPERS
Reading dial and digital caliper is very simple and straight forward, therefore, our concentration here will be reading graduated vernier caliper. Graduated vernier caliper as stated earlier on, has main scale and vernier scale, your first step will be identifying the number of division that the vernier scale of the caliper you are using has. We have 10 division vernier caliper, and each mark is 0.01cm; we also have 20 division and each mark is 0.005cm, finally we have 50 division and each mark is 0.002cm, therefore we can conclude that the more the division the more accurate the vernier caliper. Another difficult task is detecting the point of concidence of a specific mark on Vernier Scale and another mark on the main scale.

VERNIER CALIPER


This diagram above is a zoomed view of the scale reading of a given caliper. All you need to accurately read the caliper is to add the main scale to the vernier scale. You simply must note that the main scale is 10 times greater than the vernier scale; or better put it that the main scale is in centimeters while the vernier is in millimeters. Therefore, adding the main scale to the vernier scale involves you converting it to centimeters; or converting the main scale to millimeters. In summary both scale must be in the same unit, before one can add them. Some examples will ensure you understand it properly.
Examples: this is for 10-division vernier Caliper Reading

10 DIVISION VERNIER CALIPER


Examples: this is for 20-division vernier Caliper Reading

20 DIVISION VERNIER CALIPER


5. Micrometer Screw gauge: this instrument just like meter stick and vernier caliper is used in the measurement of distance, but in this case very small distance. Micrometer Screw gauge is 10 times more accurate than the vernier calipers, therefore is a very accurate instrument. Its accuracy is 0.001cm. Working with vernier caliper also requires a special topic and practical for one to be able to use it effectively.

MICROMETER SCREW GAUGE


READING MICROMETER SCREW GUAGE


6. Spring Balance: another property of matter that scientists desire to know is it mass or weight, starting from electron, atom, a newly born baby, adult, rice, meat among so many other matters.

SPRING BALANCE


7. Triple Beam Balance: this instrument applies the concept of equilibrium of standard masses and unknown mass to fine the mass of a given object under investigation. It is equipped with three known masses sliding through three beams just to balance an unknown mass whose mass is being calculated.

TRIPLE BEAM BALANCE


8. Double pan balance: this instrument also employs the concept of equilibrium of masses to determine an unknown. It is equipped with two pans and standard masses needed for finding out the mass of an unknown object.

DOUBLE PAN BALANCE


9. Stop watch: this instrument is a clock that helps one determine time taking for a given experimentation to be concluded. In most cases we use it during heat experiment and pendulum bob experiments.

STOP WATCH


10. Voltmeter: this is used in the determination of potential difference, voltage drop or electromotive force (EMF) within an electrical circuit. One of the characteristics one wish to know during electrical test is the voltage drop at various sections in the system. Voltmeter is the instrument for this purpose. We have both analog and digital voltmeters.

VOLTMETER


11. Ammeter: this instrument is used in the determination of the quantity of current flowing in a given circuit. Electrical current is also another important characteristics one also wish to know while working in electrical circuits, because without such knowledge your electrical system operation cannot be known.

AMMETER


12. OHMMETER: this instrument is used in the measurement of electrical resistance. If we want to determine the value of a given resistor, this instrument is used.

OHMMETER


13. Multimeter: this instrument can measure two or more electrical characteristics, that is to say it has voltmeter, ammeter, ohmmeter e.t.c. as a single unit.
MULTIMETER


QUESTIONS
 1.  Define Physics.
 2.  Define Practical Physics.
 3.  What are the objects of study in Physics?
 4.  What is meter stick and its application?
 5.  What is the accuracy of the meter stick?
 6.  What are the five types of caliper?
 7.  What are the various types of inside/outside caliper?
 8.  What is caliper and its application?.
 9.  What is meter stick and its application?.
 10.  An incomplete ruler measure a short distand, the lower mark is at 72.5c, while the upper mark is at 83cm; what is the lenght of the object measured in cm and mm.