MARKING SCHEME - CBSE

1 MARKING SCHEMECLASS XIISCIENCE SUBJECTSCENTRAL BOARD OF SECONDARY EDUCATIONDELHI2012 CBSE, Delhi-110301 Published by Secretary, 'Shiksha Kendra', 2, Community Centre, Preet Vihar, Delhi - typesetting and Printed by Akashdeep Printers, Daryaganj, New Delhi - 110002 Manuscript as such highlights the main value points and does not represent a complete ideal may vary from time to time and year to : , 2012 : 250 CopiesPREFACECBSE as a pace setting national Board has constantly been striving to design its evaluationprocess in a manner that it is used as a powerful means of influencing the quality of teaching and learningin the classroom situation. Also, it has to be so designed that it provides constant feedback regardingthe effectiveness of the course content, classroom processes and the growth of individual learnersbesides the appropriateness of evaluation a move in this direction, CBSE started the practice of publishing the MARKING schemes withtwin objectives in mind-(i) making the system more transparent and at the same time, (ii) ensuring highdegree of reliability in scoring are the markers of answer scripts?

2 How do they mark the answer scripts? How can it beensured that MARKING is fair, objective and reliable? Questions of these types naturally arise in the mindsof candidates appearing in the public examination. These questions are equally pertinent to the teacherswho are not adequately exposed to the CBSE system of Scripts MARKING is a specialised job. It is assigned to teachers-PGTs for class XII andTGTs for class X who are in direct touch with the subject and have a minimum of 3 years experienceof teaching the subject at that level. Appointment of examiners is made in accordance with the well-defined norms. Markers examine scripts with the help of detailed guidelines called the ' MARKING schemes '.It is this tool ( MARKING SCHEME ) alongwith the extensive supervisory checks and counter-checksthrough which CBSE tries to ensure objective and fair MARKING .

3 The present publication is being broughtout with a view to serving the following objectives :(i)To give an opportunity to the teachers and students to look into the MARKING schemes thatwere developed by the Board and supplied to the evaluators in 2012 main examination insome selected main subjects.(ii) To receive feedback and suggestions from institutions/subject teachers on the utility andfurther improvement of MARKING schemes .(iii) To encourage institutions to undertake similar exercise of developing MARKING schemes forclasses other than those covered by the Board's examination with a view to increasingteachers' responsiveness to them as the essential tools of evaluation.(iii)HOW TO USET eachers and the students preparing for class XII examination of the Board constitute theprimary interest-group of this publication.

4 MARKING schemes of Question Papers in the subjects ofEnglish Core, Functional English, Mathematics, Physics, Chemistry, Biology, Bio-Technology, InformaticsPractices, Computer Science, Engineering Drawing and Multimedia & Web Technology administeredin Delhi and Outside Delhi during the 2012 main examination have been included in this tips on their usage are given below :(a)To Teachers :---Go through the syllabus and the weightage distribution for the subject the question paper to find out how far the question paper set subscribes to theprescribed design. Grade every question by difficulty level for students who have taken themain Board the ' MARKING SCHEME ' for each question, with reference to steps into which answersand awards have been out concrete suggestions for the Board.

5 (b)To Students :---Study each question carefully, comprehend them and write down the main points of theanswer and note down their difficulties for a question in conjunction with the MARKING SCHEME and find out the proximity ofthe answer to that suggested in the MARKING urge the teachers to encourage their students to make use of this SHARMACONTROLLER OF EXAMINATIONS(iv)CONTENTSS enior School Certificate Examination (XII) MARKING SchemePage Core .. English .. Practices .. Science .. Graphics .. and Web Technology ..449-502(v)LIST OF COORDINATORS/SUBJECT EXPERTS/REPRESENTATIVESOF THE REGIONS FOR UPDATION/FINALISATION OF THEMARKING SCHEME FOR THE SENIOR SCHOOL CERTIFICATEEXAMINATION, of the of the Coordinator/SubjectExperts(vi) Felix MartisLoyola High School,Khurji, PO Sadaqat Ashram,Patna, Vikram JoshiPrincipal,Jawahar Navodaya Vidyalaya,Rudrapur,Udham Singh Nagar, ChandPGTG lobal Gurukul Institute School,Mani Majra, Public SchoolHauz Khas, New Delhi - DastidarPrincipalArmy School, Narangi,PO-Satgaon,Guwahati - Sudesh AroraLaxman Public SchoolHauz Khas, New Delhi - Navin SharmaLaxman Public SchoolHauz Khas, New Delhi - 16 ENGLISH Usha RamPrincipalLaxman Public SchoolHauz Khas, New Opkar SinghRetd.

6 , Sahyog AppartmentsMayur Vihar Bella Bhateja,PGTG. D. Goenka Pub. SchoolVasant Kunj,New Sanjeevan BosePGTS cindia SchoolThe Fort, Vandana DAV Public SchoolMausam Kanti RamakrishnanVice PrincipalChinmaya Vidyalaya,9 B Taylors Road, Kilpauk, of the of the Coordinator/SubjectExperts(vii)FUNCTIONA L Annie KoshyPrincipalSt. Mary's SchoolB-II Block, Safdarjung EnclaveNew Usha RamPrincipalLaxman Public SchoolHauz Khas, New Malini KhatriModern SchoolBarakhamba RoadNew Neena s SchoolB-II Block, Safdarjung EnclaveNew S. LahiriSt. Mary's SchoolB-II Block, Safdarjung Enclave,New SrinivasanPrincipal,P. S. Sr. Sec. School,33, AlarmelmangapuramMylapore, P. J. PeterPGTL axman Public SchoolHauz Khas, New Shailja JaiswalPGTD elhi Public SchoolSite No. 3, Meerut Road,Ghaziabad - Anita Public SchoolBU Block, Pitampura, V.

7 P. GuptaRetired ProfessorKala Vihar Appartments,Mayur Vihar, G. D. DhallK-171, LIC ColonySyed Nangloi ChibberPrincipal (Retd.)B-330, Saraswati J. C. NijhawanRtd. PrincipalC-51, Maharana Pratap Enclave, Rajpal,PGTP ratibha Vikas Vidyalaya,Gandhi Nagar, Delhi-110051(218, Maitrye Extn., Patparganj, Delhi) AlamVice PrincipalSt. John's Sr. Sec. School,Bundi Road,Kota-324008 (Rajasthan) of the of the Coordinator/SubjectExperts(viii) D. R. Sharma,Vice-PrincipalJNV, Mongal Saha,Vice Principal,Army School, Narangi,PO-Satgaon, C. SathyamurthyPrincipalChinmaya Vidyalaya9-B, Taylore RoadKilpauk S. D. Arora,Principal,Kendriya Vidyalaya Lines,Rae Bareli, Saroj Gupta,Principal,DTEA Sr. Sec. School,Sector-4, Puram, ChaubeyJawahar Lal MemorialSr. Sec. SchoolDigwadih No.

8 12, Pathardih, Dhanbad, SatpathyPrincipal,DAV Pub, School,Chandrasekharpur,Bhubaneshwar, SinghRetired Principal2610 A, Street Colony Shahdara, SinghA-64, F-3, Ram PrasthaGhaziabad ( ) Parveen KumarPGTS. D. Public School,BU Block, Ajay MarwahaPGT (Mathematics) Public SchoolBU BlockPitampura, BediPrincipalApeejay School,Road No. 42, Sainik Vihar, of the of the Coordinator/SubjectExperts(ix) BhasinB4/46 Paschim Vihar,New SehgalA-94/1, SFS Flats,Saket, New G. GiriHead MasterModern SchoolBarakhamba RoadNew Suraj PrakashRetd. PrincipalQU-290 - B,Chitrakoot Delhi - Thakur,Vice PrincipalHE Vikram Hr. Sec. School,BHEL, PiplaniBhopal - L. Neelakanta Pillai,PrincipalKola Perumal Chetty VaishnavSr. Sec. School815, EVR Periyar High Road,ArumbakkamChennai, Dinesh Bartwal,Vice PrincipalDoon International School,32, Curzon Road Nilakantha PanigrahiVice PrincipalSai International School,5A, Chandaka Indust.

9 Estate,Infocity Road, , Bhubaneswar (Odisha) Surjan SinghPGTCRPF Public School,Sector-XIV, Rohini, Kiran NayakApeejay School,Road No. 42,Sainik Vihar, Ravinder KaurPGTGovt. Model Sr. Sec. SchoolSector Margaret Pub. SchoolD-Block Prashant Uppadhyay,326 SFS FlatsAshok Vihar Shukla,40, Delux , Vasundhara of the of the Coordinator/SubjectExperts(x) MishraRetd. PrincipalB-203, Saraswati Vihar, Rakesh DhawanPGTSt. Margaret Public SchoolPrashant Deshbir Singh,PGTSt. Paul's Hr Sec. SchoolBoundary Road, Avinash Kumar VohraPGTGovt. Model Sr. Sec. SchoolSector-35, GondPrincipalKendriya Vidyalaya No. 2,Itanagar, Distt. Pampumpare,Arunachal Abdul RaheemVice PrincipalSPDH Sindhi Model Sr. Sec. School1, Danodara StreetKellys, PanditPrincipalGodwin Public SchoolRohta Road, FazalpurMeerut ( ) - (Mrs) Sangeeta BhatiaPrincipalKIIT World SchoolPitampura, Near Club, SinghJawahar Vidya MandirShyamli, Ranchi, Mrs.

10 Bhagwati NayakPrincipalDAV Public School, Unit-8,Post office Naya PalliBhubneshwar-751012 (Odisha) Rachna Gupta,HeadmistressDelhi Public SchoolSector C Poket 5,Vasant Kunj, New PurangRetd. ADEC2/113, Janakpuri,New TalwarRetd. Principal54, Khan MarketNew Virendra SrivastavaB-3B/95 BJanakpuriNew of the of the Coordinator/SubjectExperts(xi) Shivani Goswami,563, Golf Vista Apptts,Alpha-II, Sector, Greater Noida,Gautam Budh Nagar ( ) Kamaljeet KaurPGTGovt. Model Sr. Sec. Laxmi Narayanan,Principal,Kendriya Vidyalaya, AFS,Digaru, Sonapur, Kamrup, Margarette DavidrajPrincipalBakthavatsalam Vidyashram14, 31st Street, TNHB Colony,Periyaar Nagar, Korattur, Neeta RastogiPrincipalSadhu Vaswani Int. School for Girls2nd Street, Shanti NiketanNew PrasadDAV Public SchoolCantonment Area,Gaya (Bihar) Shankar Bardhan,Vice Principal,Hem Sheela Model SchoolJawahar Lal Nehru Avenue,Durgapur, Barddhaman,West Bandana LazarusDelhi Public School,Vasant Kunj,New S.