O slideshow foi denunciado.
Utilizamos seu perfil e dados de atividades no LinkedIn para personalizar e exibir anúncios mais relevantes. Altere suas preferências de anúncios quando desejar.

Factors on which the internal resistance/emf of a cell depends

83.979 visualizações

Publicada em

(CBSE class 12 project on) study of various factors on which the internal resistance/emf of a cell depends.

Publicada em: Ciências
  • Sex in your area is here: www.bit.ly/sexinarea
       Responder 
    Tem certeza que deseja  Sim  Não
    Insira sua mensagem aqui
  • Dating for everyone is here: www.bit.ly/2AJerkH
       Responder 
    Tem certeza que deseja  Sim  Não
    Insira sua mensagem aqui
  • DOWNLOAD THIS BOOKS INTO AVAILABLE FORMAT (Unlimited) ......................................................................................................................... ......................................................................................................................... Download Full PDF EBOOK here { https://tinyurl.com/y6a5rkg5 } ......................................................................................................................... Download Full EPUB Ebook here { https://tinyurl.com/y6a5rkg5 } ......................................................................................................................... ACCESS WEBSITE for All Ebooks ......................................................................................................................... Download Full PDF EBOOK here { https://tinyurl.com/y6a5rkg5 } ......................................................................................................................... Download EPUB Ebook here { https://tinyurl.com/y6a5rkg5 } ......................................................................................................................... Download doc Ebook here { https://tinyurl.com/y6a5rkg5 } ......................................................................................................................... ......................................................................................................................... ......................................................................................................................... .............. Browse by Genre Available eBooks ......................................................................................................................... Art, Biography, Business, Chick Lit, Children's, Christian, Classics, Comics, Contemporary, Cookbooks, Crime, Ebooks, Fantasy, Fiction, Graphic Novels, Historical Fiction, History, Horror, Humor And Comedy, Manga, Memoir, Music, Mystery, Non Fiction, Paranormal, Philosophy, Poetry, Psychology, Religion, Romance, Science, Science Fiction, Self Help, Suspense, Spirituality, Sports, Thriller, Travel, Young Adult,
       Responder 
    Tem certeza que deseja  Sim  Não
    Insira sua mensagem aqui
  • Sex in your area for one night is there tinyurl.com/hotsexinarea Copy and paste link in your browser to visit a site)
       Responder 
    Tem certeza que deseja  Sim  Não
    Insira sua mensagem aqui
  • Girls for sex are waiting for you https://bit.ly/2TQ8UAY
       Responder 
    Tem certeza que deseja  Sim  Não
    Insira sua mensagem aqui

Factors on which the internal resistance/emf of a cell depends

  1. 1. Satya Prakash Public School Physics Project Topic : Study of various factors on which the b internal resistance/EMF of a cell b b depends. Submitted to : Mr. Rajesh Kaurav Submitted by : Harsh Solanki [class- 12th ]
  2. 2. Certificate This is to certify that Master Harsh Solanki, a student of class 12th(science) has successfully completed his project work under the guidance of subject teacher Mr. Rajesh Kaurav during the year 2016/2017 from Satya Prakash Public School in partial fulfillment of physics practicle examination conducted by CBSE. ______________________________11111111111111111111_________________________________ Teacher In-charge External Examiner ____ Principal School Rubber Stamp00
  3. 3. Acknowledgement The success and final outcome of this project required a lot of guidance and assistance from many people and I am extremely fortunate to have got this all along the completion of my project work. Whatever I have done is only due to such guidance and assistance and I would not forget to thank them. I respect and thank Mr. Rajesh Kaurav, for giving me an opportunity to do this project work and providing us all support and guidance which made me complete the project on time. I would like to express my gratitude towards Mrs. Rakhi Mukherjee for helping me in conducting practicals for project. Last but not the least I would like to thank all my friends who supported me all the way and my parents who helped me financially and encouraged me throughout in the completion of project.
  4. 4. 1. 2. S no. Introduction  Internal Resistance Practical Analysis  Objective  Apparatus  Theory  Circuit Diagram  Procedure  Result & Inferences  Precautions  Sources of error Flowchart Conclusion Bibliography INDEX Topics 3. 4.
  5. 5. INTRODUCTION There is a great need of batteries in our daily use electronic appliances and the use is increasing every day. Thus , the batteries need to be made more powerful so that their potential can be increased greatly . Thus , this project report is based on practical analysis for the factors affecting the internal resistance of a cell. When the internal resistance of the cell is decreased we can increase the potential difference across it , and hence make it more reliable.
  6. 6. INTERNAL RESISTANCE Internal resistance is defined as the resistance offered by the electrolyte of the cell to the flow of ions.  Its S.I. unit is Ohm (Ω) For a cell of e.m.f. (E) and internal resistance (r), connected to an external resistance (R) such that (I) is the current flowing through the circuit, E = V + Ir Internal Resistance r = E–V O I
  7. 7. PRACTICAL ANALYSIS OBJECTIVE To study the various factors on which the internal resistance of a cell depends. APPARATUS A potentiometer, a battery (or battery eliminator), two one way keys, a rheostat, a galvanometer, a resistance box, an ammeter, a cell (Leclanche cell), a jockey, a setsquare, connecting wires and sand paper. THEORY The internal resistance of a cell is the resistance offered by its electrolyte to the flow of ions . The internal resistance of a cell  is directly proportional to the distance between the electrodes.
  8. 8.  is inversely proportional to facing surface area of the electrodes in electrolyte.  decreases with increase in temperature of electrolyte.  is inversely proportional to concentration of electrolyte. The internal resistance of a cell is given by: CIRCUIT DIAGRAM r = (E-V)/I
  9. 9. PROCEDURE 1.Clean the ends of the connecting wires with sand paper and make tight connections according to the circuit diagram. 2. Tighten the plugs of the resistance box. 3. Check the e.m.f. of the battery and of the cell and make sure that e.m.f. of the battery is more than that of the cell, otherwise null or balance point will not be obtained. To study variation of internal resistance with distance of separation 4.Keep both the electrodes at a distance of 16 cm. 5.Take maximum current from the battery, making rheostat resistance small. 6.Without inserting a plug in key K2, adjust the rheostat so that a null point is obtained on the last wire of the potentiometer. 7. Determine the position of the null point accurately using a set square and measure the balancing length (l1) between the null point and the end P. 8.Next introduce plugs in both keys K1 and K2. At the same time, take out a small resistance (1 – 5 W) from
  10. 10. the shunt resistance box connected in parallel with the cell. 9.Slide the jockey along a potentiometer wire and obtain the null point. 10. Measure the balancing length (l2) from end P. Record these observations. 11. Now keep the electrodes 12 cm apart. 12. Then remove the plugs of keys K1 and K2. Wait for some time and repeat steps 7 to 10. 13. Next, keep the electrodes 9 cm apart to obtain another set of observations. To study variation of internal resistance with area of electrodes 14. Keeping all other factors constant, increase the area of electrodes in the electrolyte by dipping them into the electrolyte at different depths for each observation. 15. Obtain three such observations by repeating steps 7 to 10. Record your readings. To study variation of internal resistance with concentration of electrolyte
  11. 11. 16. Keeping all other factors constant, decrease the concentration of electrolyte by adding distilled water for different observations. 17. Obtain three such observations by repeating step 7 to 10. Record your readings. OBSERVATIONS S.no. Ammeter Reading (A) Position of null point(cm) Shunt Resistance R(Ω) Internal Resistance r(Ω)With R (l1) Without R (l2) 1. 0.3 660.5 35.5 1 0.94 2. 0.3 660.5 77.2 2 1.77 3. 0.3 660.5 108.3 3 2.51 Table for effect of separation between electrodes S.no. Separation between electrodes d (cm) Balancing point Balancing point Internal Resistance r(Ω) r/d l1(cm) l2(cm) 1. 1.2 326.6 276.9 0.456 0.38 2. 2.5 320.7 219.1 0.95 0.38 3. 3.7 660.5 350.9 1.406 0.38
  12. 12. Table for effect of temperature S.no. Temperature T (o C) l1(cm) l2(cm) Resistance R(Ω) Internal Resistance r(Ω) Tr (ΩK) 1. 1.2 326.6 276.9 0.456 0.38 301.44 2. 2.5 320.7 219.1 0.95 0.38 291.96 3. 3.7 660.5 350.9 1.406 0.38 283.87 RESULT & INFERENCES  The Electromotive Force of the cell is constant and is equal to E = 0.98 Volt.  The internal resistance of a cell is directly proportional to the separation between the electrodes.  The internal resistance of a cell is inversely proportional to the area of the electrodes dipped in electrolyte.  The internal resistance of a cell is inversely proportional to the temperature of electrolytes.  The internal resistance of a cell is inversely proportional to the concentration of the electrolyte.
  13. 13. PRECAUTIONS 1.The connections should be neat , clean and tight. 2.The plugs should be introduced in the keys only when the observations are to be taken. 3.The positive polls of the battery E and cells E1 and E2 should , all be connected to the terminal at the zero of the wires. 4.The jockey key should not be rubbed along the wire. It should touch the wire gently. 5.The ammeter reading should remain constant for a particular set of observation. If necessary , adjust the rheostat for this purpose. SOURCES OF ERROR 1.The auxiliary battery may not be fully charged. 2.The potentiometer wire may not be of uniform cross- section and material density throughout its length. 3.End resistances may not be zero.
  14. 14. Factors Affecting Internal Resistance of a Cell Distance between Electrodes Area of Electrodes Inversely Proportional Temperature of Electrolytes Inversely Proportional Conc. of Electrolyte Inversely Proportional FLOWCHART CONCLUSION Directly Proportional
  15. 15. BIBLIOGRAPHY  www.google.com  www.documents.mx  www.wikipedia.org  www.docfoc.com  www.slideshare.net

×