physics project final.pptx

8/10/2019 Physics Project Final.pptx

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- BY- ATHARVA TANKSALE (12

th

B)


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CERTIFIC TE

This is to certify that the work presented anddone in this Project Report ,has been carried outin the Physics Laboratory during the presence ofMs. Manju Ma'am.

The project submitted has entirely been done

and completed by me and my friend ShreenathRao under the guidance of Ms. Manju Maam.

Signature;-

Date:-


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Acknowledgements

I, Atharva Tanksale would like to take upthis opportunity to thank the guidance

given to me by Ms. Manju Maam, for the

completion of this project. I would also like

to make use of this opportunity to thank

our Principal Ms. Kelkar Maam for

allowing me to use the Physics lab. Special

thanks to Shreenath Rao, my classmatewho assisted me in this project.


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TABLE OF CONTENTS1)Acknowledgements

2)Introduction

3) Theory of the Experiment

4) Basics of the Wheatstone Bridge

5) Mathematics Of the Wheatstone Bridge6) Materials Required

7) Procedure

8) Observations

9) Conclusion

10)Few Glimpses

11)Bibliography


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INTRODUCTION

Pure water does not conduct electricity, but anysolvated ionic species would contribute toconduction of electricity.

An ionically conducting solution is called anelectrolyte solution and the compound, which

produces the ions as it dissolves, is called anelectrolyte

A strong electrolyte is a compound that willcompletely dissociate into ions in water.

Correspondingly, a weak electrolyte dissolves only

partially. The conductivity of an electrolytesolution depends on concentration of the ionicspecies and behaves differently for strong andweak electrolytes.


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Theory of the Experiment

1). Movement of ions in water can be studied by installing a pair

of electrodes into the liquid and by introducing a potentialdifference between the electrodes. Like metallic conductingmaterials, electrolyte solutions follow Ohmslaw:

R=V/Iwhere R is the resistance (ohms),V is the potential difference

(V, Volts),and I is the current (A, Amperes).2). Conductance G (S,Siemens) is defined as reciprocal of theresistance:

G=1/RConductance of a given liquid sample decreases when thedistance between the electrodes increases and increases whenthe effective area of the electrodes increases. This is shown inthe following relation:

G=KA/Lwhere K is the conductivity (S /m), A is the cross-sectional areaof the electrodes ( e.g. the effective area available for conducting

electrons through the liquid), and l is the distance between theelectrodes .


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Basics of the Wheatstone Bridge

The Wheatstonebridge is an electricalbridge circuit used tomeasure resistance.

It consists of a

common source ofelectrical current(such as a battery)and a galvanometer

that connects twoparallel branches,

containing four

resistors, three ofwhich are known.

One parallelbranch contains

one known

resistance andan unknown theother parallel

branch containsresistors of

knownresistances (R1

and R2).

Due to theiroutstandingsensitivity,

Wheatstone bridgecircuits are very

advantageous forthe measurement

of resistance,inductance, and

capacitance.


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Wheatstone ridge


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The Mathematics of Wheat Stone Bridge

The value of an unknown resistance by comparing it with aknown one. Three known and adjustable resistances are

connected with the unknown resistance, a galvanometer/a power supply, and a key, as shown in the previous page,for a condition of balance, so that no current flows throughthe galvanometer. Hence the current through R1 is thesame as the current through R2, and the current throughR3is the same as that through R4. Also, the potential dropacross R1is equal to that across R3.

i1R1= i2R3 ___________________(1)Similarly, the potential drop across R2 is equal to thatacross R4

i1R2= i2R4____________ (2)

Dividing the first equation by the second, one finds therelation

R1/R2=R3/R4__________ (3)Therefore, if three of the resistances are known, the fourthmay be calculated by using the above relation.


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MATERIALS REQUIRED

CARBON ELECTRODES

WHEATSTONE BRIDGE SETUP

RESISTANCE BOX

GALVANOMETER

JOCKEY

BATTERY ELIMINATOR

COPPER SULPHATE SOLUTIONS OFDIFFERENT MOLARITIES

DILUTE SOLUTION OF SULPHURIC ACID


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PROCEDURE

1. Connect the slide wire form of the bridge as shown onthe next page. Let X be the unknown resistance of the

prepared solution of Copper Sulphate.

2. Measure the resistance of the solution with the bridge. To

obtain a balance, set the sliding key in the center of thebridge wire and adjust the jockey until a

minimum deflection of the galvanometer. When the bridgeis balanced, measure the lengths obtained using the

attached meter scale.

3. Record the values of the standard resistances and of thelengths obtained. Record two more readings by altering the

values of the known resistance


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OBSERVATIONS

At concentration of electrolyte 0.1M

S.No Value ofknownresistance

Length(l) 100-l Resistance(S)

1 1500 55 45 1833

2 1700 51.9 48.1 1834.3

3 1900 49.6 50.4 1869.8

1845.8


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S.No Value ofknown

resistance


1 3000 41.5 58.5 2128.20

2 4000 34.3 65.7 2088.28

3 2000 51.2 48.8 2098.36

2104.92


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S.No Value ofknownresistance


1 3000 46 54 2555.6

2 4000 39 61 2557.3

3 5000 34.1 66.2 2587.2

2566.86


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CONCLUSIONS

Based upon the Experiments conducted by us we havecome to the following conclusions-

1. The Resistance of the Copper Sulphate Solutionincreased with increase in the concentration of the

solute.

2. The values of Conductance's kept on decreasing as theconcentration of the solute was increased. This provesthat the value of Conductivity is inversely proportional

to that of Resistance.

C

3. It has been observed that the values of Resistancechange much on the increase of concentration. This

proves that Copper Sulphate is a weak electrolyte.


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FEW GLIMPSES OF THE WORK


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BIBLIOGRAPHY

NCERT Physics Textbook Class 12th

NCERT Chemistry Textbook Class 12th

Concepts of Physical Chemistry : Dr. P.Bahadur

Modern approach to Chemical Calculations

: Dr. R.C. Mukherjee

physics project final.pptx

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