Tuesday, 3 May 2016

Summer Vacation Holiday Homework Class XII



Subject: English         

 
1.      Solve 4 unseen reading comprehension passages (2 of each kind).
2.      Learn and write the difficult words-meanings, Q-A, summary of the novel- Chapters1-4.
3.      Section B Writing (Write 1 each)
Notice, Advertisements(2 kinds), Posters,Reports writing, Factual Description, process writing, Letter writing 4 types(1 each), Articles -2, Speeches -2, Debates-2,
4.      Write and learn the vocabulary words of lessons-  Lost spring, Deep Water, The Enemy, Should Wizard Hit money

   Subject: Physics 

Prepare a note on following topics and learnt it:

Chapter–2: Electrostatic Potential and Capacitance
·         Electric potential
·         Potential difference.
·         Electric potential due to a point charge.
·         A dipole and system of charges.
·         Equipotential surfaces.
·         Electrical potential energy of a system of two point charges and of
·         Electric dipole in an electrostatic field.
·         Conductors and insulators, free charges and bound charges inside a conductor.
·         Dielectrics and electric polarisation
·         Capacitors and capacitance.
·         Combination of capacitors in series and in parallel.
·         Capacitance of a parallel plate capacitor with and without dielectric medium between the plates.
·         Energy stored in a capacitor.
·         ALSO SOLVE THE NCERT QUESTION


Chapter–3: Current Electricity
·         Electric current
·         Flow of electric charges in a metallic conductor
·         Drift velocity, mobility and their relation with electric current
·         Ohm's law
·         Electrical resistance
·         V-I characteristics (linear and nonlinear),
·         Electrical energy and power
·         Electrical resistivity and conductivity
·         Carbon resistors, colour code for carbon resistors
·         Series and parallel combinations of resistors
·         Temperature dependence of resistance
·         Internal resistance of a cell
·         Potential difference and emf of a cell
·         Combination of cells in series and in parallel
·         Kirchhoff's laws and simple applications
·         Wheatstone bridge
·         Metre bridge
·         Potentiometer - principle and its applications to measure potential difference and for comparing EMF of two cells.
·         Measurement of internal resistance of a cell.
·         ALSO SOLVE THE NCERT QUESTION

Subject: Chemistry

UNIT (1) – SolidState                             Practice Paper-1                   02.05.2016

Q1 (i) Why is Frenkel defect not found in pure alkali metal halides.
      (ii) What happens to the structure of CsCl when it is heated to about 760 k?                  
      (iii) Fe3O4 is ferrimagnetic at room temperature and becomes paramagnetic at 850 K.Why?
      (iv) When atoms are placed at the corners of all 12 edges, how many atoms are present per unit cell?           4

Q2 The composition of a sample of wustite is Fe0.93O1.00. What percentage of iron is present in the form of
      Fe(III)?                                                                                                                                                               4         

Q3 Calculate the packing efficiciency in cubic close packing arrangement.                                                          4

Q4 If the radius of octahedral void is  r& radius of atoms in close packing is R, drive the relation between
      r &R.                                                                                                                                                                 4

Q5 Niobium crystallizes in body centered cubic structure. If density is 8.55 gm cm-3. Calculate atomic
      radius of niobium . Atomic mass of niobium is 93 u.                                                                                        4 

Q6 Explain the following term with suitable example
          (a) Schottky defect (b)Frenkel defect (c) Interstitials (d) F-centres                                                              4

Q7 What is a semiconductor? Describe the two main types of semiconductors & contrast their conduction  
      mechanism.                                                                                                                                                        4

Q8   (a) In terms of band theory, what is difference between
                (i) Conductor and an insulator (ii) Conductor and semiconductor                                                          2
       (b)    If NaCl is doped with 10-3 mol  %  of SrCl2 , what is the concentration of cation vacancy?                  2

Q9 (a) What type of stoichiometric defect is shown by :                                                                                       2
                (i)  ZnS            (ii)     AgBr
      (b) Classify the following as p-type or n-type semiconductor:                                                                         2
                (i)  B doped with Si     (ii) Si doped with B

Q10 (i) Why is glass considered a super cooled liquid?
        (ii) Name the parameters that characterize a unit cell.
        (iii) What is the two dimensional coordination number of a molecule in square close-packed layer ?
        (iv) Give the significance of a lattice point.                                                                                                    4

Answers→

Q1   Because ions can not get into interstitial sites due to their larger size.(b)  CsCl structure transforms into
         NaCl structure.(c) due to randomization of spins at high temp.(d) at corners 8 x 1/8 = 1 atom(ans).

Q2   Let atoms of Fe+3 = x ,  atoms of Fe+2 = 0.93—x . For electrical neutrality,
                 Total positive charge    =    Total negative charge
                 2(0.93—x ) + 3x           =    2,     then x = 0.14( Fe+3atoms), %Fe+3 = 0.14x100/0.93 = 15.05
                 % 0f Fe+2 = 100—15.05 =  84.95.

Q3   Packing efficiency in ccp or fcc = 74.06 %  derivation in book

Q4   r / R = 0.414 (ans).

Q5   Z = 2, M = 93, d = 8.55 gm/cm3, N0 = 6.022 x 1023, d = Z x M / N0 x 10—30 x a3
        Calculate a3 = 3.61 x 107 ,  a = 330.5 pm.
            
Q6  (a) Schottky—it arises if some of the atoms or ions are missing from their normal lattice sites. Equal
      number of cations and anions are missing. Density is lowered. Occurs in compounds having high C.N
      &Cations and anions are of similar size.eg Alkali metal halides (B) Frenkel—it arises if some oftheatoms                or ions are missing from their normal positions and occupy an interstitialsite between lattice points.Density           remains same. Occurs in  compounds having low C.N. Cations are smaller than anions. Ag halidesAgBr       contains both defects. (c)  Vacant sites in the structure of crystal lattice. (d) Electrons trapped in anion        vacancies arerefered as F—centres.They are responsible for colour. Nonstoichiometric KCl is violet in colour.

Q7   Those substances which are insulator at lower temperature but conduct electricity at higher temperature
       are called semiconductors.Thermal energy available at room temperature is sufficient to excite electrons
       from highest occupied band to the next permitted band.
        Intrinsic—Electrical conductivity is due to ther effect. No extra impurity is added.(Ge& Si at room temp).
        Extrinsic—Electrical conductivity is due to impurity effect. Extra substance is added. They are of two
       types, n—type and p—type.
      n-type—Electrical conductivity is due to electrons. eg group 13 elements doped with group 14 elements.
      p-type—Electrical conductivity is due to electron deficient bond or electron vacancy or holes.eg group 14
      elements doped with group 13 elements.

Q8   (a) In conductors energy gap is very-very small less than 50 kj/mole(metals).
             In insulators energy is large more than 300 kj/mole(rubber).
             In semiconductors energy gap is 30—300 kj/mole.
        (b) One cation of Sr+2 would create one vacancy. Conc of cation vacancy = 10—3mole % = 10—3/ 100 =
            10—5mole. No of Sr+2 ions in 10—5mole = 6.022 x 1023x 10—5=  6.022 x 1018 ions = cation vacancies.

Q9   (a)  ZnS—Frenkel or dislocation. AgBr—Frenkel and schottky both. (b) i—n-type, ii—p-type.

Q10  (a) Because it has  the property to flow slowly.
         (b) Three dimensions and three angles.
         (c)  Four.
         (d) lattice points are occupied by constituent particles.
Practice Paper- 2

Q1    (a)Why is the window glass of old buildings thick at the bottom?                                                                3
         (b)What happens when CaCl2 is introduced to the AgCl crystal?
         (c)What happens when CsCl is heated to 760 K?
Q2    (a)Give significance of a lattice point.
         (b)What type of defect can arise when a solid is heated? Which physical property is affected by it
             and in what way?
         (c)What is meant by co-ordination number?                                                                                                3
Q3    Analysis shows that Nickel Oxide has oxide Ni0.98O1.00. What fraction of Ni exists as Ni+3& Ni+2 ions?  3
Q4    KF has NaCl structure, What is the distance between K+ ions and F- ions, if density is 2.48 gm/cm3.       3
Q5    (a)Explain intrinsic and extrinsic semiconductors with suitable examples.                                                 3
         (b)Classify the following as n-type or p-type semiconductors
                 (i) B doped with Si   (ii)  Si doped with B
Q6    Explain the following with suitable examples                                                                                              3
                         Frenkel defect,          F-centres,             Ferrimagnetism
Q7    Derive the relation between r and R for tetrahedral void.                                                                            3
Q8    An element has BCC structure with a edge length 288 pm. The density of element is 7.2 gm/cm3.
         How many atoms are present in 208 gm of this element?                                                                           3
Q9    Calculate the efficiency of packing in case of a metal crystal for face centred cubic.                                3
Q10   A metal crystallises into two cubic phases FCC & BCC whose edge lengths are 3.5 & 3.0 A0 respectively.
          Calculate the ratio of densities of FCC & BCC.                                                                                         3


ANSWERS  
Q1  (a) Glass has the property to flow slowly (b) vacancies are created(schottky defect).
       (c) it changes to NaCl structure. C.N changes from 8 to 6
Q2  (a) particles are present on lattice points (b) schottky defects, density decreases (c) definition
Q3  NCERT page No-31, Q -1.16  Ni+2 = 96 %, Ni+3 = 4 %
Q4 Z = 4, M = 39 + 19 = 58, d = 2.48 , NA = 6.022 x 1023, calculate a (5.375 x 10—10cm )
distance between K+ and Fions  =  5.375 x 10—10cm / 2 = 2.688 x 10—10 cm.
Q5   extrinsic contains impurities & intrinsic no impurities (i) n-type (ii) p-type
Q6   definitions in book
Q7  derivation  r / R = 2.25 in book
Q8    Z = 2,  M = ?, NA = 6.022 x 1023, d = 7.2, calculate M(51.8),
         No of atoms = 6.022 x 1023 x 208/51.8 = 24.16 x 1023ANS
Q9    efficiency FCC = 74 % derivation in book
Q10  d(fcc) = 4 x M / NA x (3.5)3,    d(bcc)  = 2 x M / NA(3)3
        d(fcc) / d(bcc) = 4 x 33 / 2 x (3.5)3 = 1.26 ans
Practice paper-3

Q1   (a) Give significance of a lattice point
        (b) What type of defect can arise when a solid is heated? Which physical property is
           affected by it & in what way?
          (c) What is meant by co-ordination number?                                                                      3
Q2    Analysis shows that Nickel oxide  has the formula Ni0.98O1.00 . What fraction of Nickel
           exists as Ni+3& Ni+2 ions?                                                                                                  3
Q3     (a) Explain extrinsic and intrinsic semiconductors with examples.
          (b) Classify the followings as p-type or n-type of semiconductors
                 (i) B doped with Si   (b) Si doped with B                                                             
Q4     Derive the relation between r & R in tetrahedral void.                                                       3
Q5     An element has BCC structure with a edge length of 288 pm. The density of element is
         7.2gm/cm3. How many atoms are present in 208 gm of this element?                              3

Q6     State Henry,S law for solubility of a gas in liquid. Explain the significance of Henry,S
         Constant(KH) at the same temperature, H2 is more soluble than He in water.Which of
         them will have higher value of KH and why?                                                    1+1+1/2+1/2
Q7     Define the followings;
                   (i) Raoult,S law            (ii)  Azeotropes      (iii)  Colligative properties                     3
Q8     What do you understand by relative lowering in V.P? Show that it is a colligative
         Property. How will determine the molar mass by  relative lowering in V.P?                      3
Q9     How many ml of 0.1 M HCl are required to react completely with 1gm mixture of
          Na2CO3  and NaHCO3 containing equimolar amounts of both.                                          3
Q10   1.00 g of a non-electrolye solute dissolved in 50 g of benzene lowered the freezing point of benzene  by 0.40 K. Find the molar              mass of the solute.( Kf  for benzene = 5.12 K kg mol-1)      

ANSWERS  
             
Q1     (a) particles are presents on lattice points (b) schottky defect, density decreases (c)   definition
Q2    NCERT page 31 Q 1.16 Ni+2 =96%  Ni+3= 4%
Q3    (a) extrinsic contains impurities , intrinsic no impurities (b) (i) n-type (ii) p-type
Q4     derive r/R = 0.225

Q5     Z = 2, M =?, Na =  6.022 X 1023, No of atoms = Na x 208 / M , answer = 24.16 x 1023.
Q6     Statement,  solubility α 1/ KH, H2 has lower value of KH
Q7     definitions in book
Q8     Derivation in book
Q9      NCERT page 60 Q-2.6, ans = 158.7 ml
Q10    


UNIT(2)    —SOLUTION                                  Practice paper-1

Q 1 (i)   Which  is  more  concentrated, 1Molar  aqueous  solution  or  1 molal  aqueous  solution & why?
       (ii)  Will  the  elevation  in  boiling  point  be  same  if 0.1 mole  NaCl or  0.1 mole of  sugar is
      dissolved  in 1 L of  water?    
Equimolar  solutions  of  NaCl&  glucose  are  not  isotonic . Why?
(iv)   Distinguish  between  boiling  point  & normal  boiling  point  of  a  liquid  .               1+1+1+1                


Q 2     State  Raoult,s  law  for  solution  containing  nonvolatile  solute  in volatile  solvent.Derive  a
          Mathematical   expression  for  the  law.                                                                                       1+3          

Q 3    What  are  ideal  and  nonideal  solutions?  Give  reasons  for  their  formation . Give one  example
        in  each  case.                                                                                                                          1+1+1+1              


Q 4   What  isVant ,Hoff  factor ? What  possible  values can  it  have  if  the  solute  molecules  undergo
          (i) Association  (ii)  dissociation  in the  solution .Prove  that  osmotic  pressure  is  a  colligative
        Property.                                                                                                                               1+1+1+1


Q 5   Define  the  following   terms :                                                                                                 1+1+1+1
                  (i)     Mole fraction    (ii)  Azeotropes   (iii)    Henry,s law  (iv)  Molal  depression  constant    

Q 6   How  many  mL  of  0.1 M HCl  are  required  to  react  completely  with  1 gm  mixture  of
         Na2CO3  and  NaHCO3  containing  equimolar   amount  of  both ?                                                    4


Q 7   Calculate  the  depression  in  freezing  point  of  water  when  10 gm  of  CH3CH2CHClCOOH
         is  added  to  250 gm  of  water  .Ka= 1.4 x 10-3,  Kf = 1.86 K Kg mole-1.                                             4


Q8   Henry ,s  law  constant  for CO2  in  water  is 1.67 x 108 Pa  at  298 K. Calculate  the   quantity   of
       CO2  in   500 ml  of  soda  water  when  packed   under  2.5  Atm  CO2  pressure  at  298 K.               4
           
Q9   18  gm  of  glucose, is  dissolved  in  1 kg  of  water  in  a  saucepan.   At  what   temperature   will
        Water  boil   at  1.013 bar?  Kb  for water  is  0.52 K kg mol -1                                                                                              4    

Q10   What   volume  of  95 wt %  sulphuric  acid  (density  1.85 gm/cm3 )  and  what  mass  of   water
         must  be  taken  to  pre pare  100 cm3  0f  15 wt  % solution  sulphuric  acid  (density 1.10 gm/cm3) 
                                                                                                                                                                   2+2
Answers→

Q1    (i) 1 Molar because it contains both solvent & solute.(ii) No. More in case of 0.1M NaCl because it
           dissociates into ions.(iii) NaCl dissociates to give ions & osmotic pressure is directly proportional to
           number of particles.(iv) b.p is when v.p of liquid becomes equal to surrounding pressure.Normalb.p
            is the temp at which v.p is 1 atm.



Q6       mass of mixture = 1gm , let Na2CO3 = x gm,  mass of NaHCO3 = 1—x , moles of Na2CO3 = x / 106.
            Moles of NaHCO3 = 1—x / 84.   equivimolar mixture means  x/106 = 1—x / 84.  x = 0.557
           Mass of Na2CO3 = 0.557gm, mass of NaHCO3 = 1—0.557 = 0.443gm.
           Na2CO3     +   2 HCl           2 NaCl+  H2O    +    CO2
           106gm            2x36.5=73                106 gm  Na2CO3need  = 73gm HCl
                                                                    0.557gm will need       = 73 x 0.557 / 106 =0.384gm HCl
           Similarly—
             NaHCO3   +   HCl               NaCl+  CO2   +  H2O
            84gm               36.5gm                    84gm   NaHCO3 need = 36.5gm HCl
                                                                    0.443 will need            = 36.5x 0.443 / 84 = 0.192gm HCl
                                                                   Total HCl used = 0.384 + 0.192 = 0.576gm
 MHCl=  moles of HCl / vol in L
               0.576/ 36.5
0.1 =  — -------- ,    V =   0.157 Litre(ans)
                      V

Q7    . Molar mass of CH3CH2CHClCOOH = 122.5,
                                               moles of CH3CH2CHClCOOH= 10/122.5 = 0.0816, m = 0.0816/ 0.250kg = 0.3264
                     α = √ Ka/C = √ 1.4 x 10—3/ 0.3264 = 0.065,            i—1                    i—1        i—1
                                                                                              α = --------,  0.065 = -------- = -------,  i = 1.065
                                                                                                      m—1                  2—1        1
                  ∆Tf = i x Kf x m = 1.065 x 1.86 x 0.3264 = 0.650 (ANS)
Q8

Q9                 Moles of glucose = 18 g/ 180 g mol–1 = 0.1 mol
                                                                                  Number of kilograms of solvent = 1 kg
                                                                                  Thus molality of glucose solution = 0.1 mol kg-1
                                                                                  For water, change in boiling point
                              ÄTb = Kb × m = 0.52 K kg mol–1 × 0.1 mol kg–1 = 0.052 K
                                                                                 Since water boils at 373.15 K at 1.013 bar pressure,therefore, the boiling point of solution will be 373.15 + 0.052 = 373.202K.

Q10   M of 95 % H2SO4 = moles x 1000 / V of solution in L
          Moles of  H2SO4  = 95/98, volume of solution = m/d = 100/1.85 = 54.05ml.
M  =  95 x 1000/ 98 x 54.05 = 17.93 M
          Similarly Molarity of 15% H2SO4 can be calculated as—         moles = 15/98, V = 100/1.10 = 90.91ml
                                 M   = 15 x 1000 / 98 x 90.91 = 1.68 M
          Apply molarity equation     M1V1       =      M2V2
                                                           95 %                 15 %
                                                   17.93 x V1      =     1.68 x 100 ,            V1  = 9.37 ml (ans)
       Mass of 100 ml 15 %  H2SO4to prepared =  1.10 x 100 = 110 gm
       Mass of 9.4 ml H2SO4 of 95 % = 9.4 x 1.85 = 17.4 gm,  Mass of H2O  =  110—17.4 = 92.6 gm(ans)


Practice paper-2
Q1    (a)Why is elevation in boiling point of water different in the following cases;                                             3
                (i) 0.1 M  NaCl solution  (ii)  0.1 M sugar solution
           (b)Which is more concentrated 1 M or 1 m solution & why?
           (c)Two liquids A & B boil at 1450C 1900C respectively. Which of them will have higher V.P at 800C?
Q2     State Henry,S law for solubility of a gas in liquid.Explain the significance of Henry,S constant(KH).         
          At the same temperature, H2 is more soluble than He in water. Which of them will have higher value of
KH& Why?                                                                                                                                                 3
Q3     Define the terms: (a) Raoult,Slaw       (b) Azeotropes     (c)  Colligative properties                                      3
Q4     What do you understand by relative lowering in V.P? Show that it is a colligative property. How will you
determine the molar mass of by relative lowering in V.P ?                                                                           3
Q5     What are ideal and non-ideal solutions? Discuss the positive and negative deviations from ideal
behavior with the help of graphs.                                                                                                             3
Q6     Calculate (a) Molality  (b) Molarity and (c) Mol fraction of KI if density of 20 % (mass/mass) aqueous
          KI is 1.202 gm /ml. (K = 39,  I = 127).                                                                                                         3
Q7     Vapour pressure of pure liquids A & B are 450 and 700 mm Hg respectively at 350 K. Find the
         composition of liquid mixture if total VP is 600 mm Hg. Also find the composition in vapour phase.      3
Q8     How  many  mL  of  0.1 M HCl  are  required  to  react  completely  with  1 gm  mixture  of
          Na2CO3  and  NaHCO3  containing  equimolar   amount  of  both ?                                                            3
Q9     Two elements A & B form compounds having formula AB2 and AB4. When dissolved in 20 gm benzene
          1 gm of AB2 lowers the freezing point by 2.3 K whereas 1 gm of AB4 lowers it by 1.3 K. Kf for benzene
         is 5.1 K kg mol—1. Calculate atomic masses of A & B.                                                                              3
Q10    Calculate the depression in freezing point of water when 10 gm of CH3CH2CHClCOOH is added to
           250 gm of water.(Ka = 1.4 x 10—3,  Kf = 1.86 =  K kg mol—1 . C = 12, H = 1, Cl =35.5, O =16)             3
Answers-
1
(a) 0.1M NaCl  due to more number of ions (b) 1Molar because it contains solvent & solute both(c) liq A
2
statement,   Solubility α 1 / KH,   H2  has lower value of KH
3
definitions, Q4- derivation, Q5- book,
4
book
5
book
6
NCERT page 37( 2.5) m =1.5, M = 1.44,  XKI = 0.0263
(a) mass of solvent = 100—20 = 80gm = 0.08 kg,  molar mass of KI = 166, moles of KI= 20/166= 0.120
            m = 0.120/0.08 = 1.5
 (b) vol of solution = m/d = 100/1.202 = 83.2ml= 0.0832 L, M = 0.120/ 0.0832 = 1.44,
(c) moles of H2O = 80/18= 4.44, XKI = 0.120/0.120 +4.44 = 0.0263
7
 NCERT PAGE 47(2.8)  XA = 0.40,  XB = 0.60,  vapour pressure XA = 0.30,  XB = 0.70
PA0 = 450, PB0 = 700 , Total = 600mm of Hg, Raoults law(PTOTAL) = PA0  + PB0 = PA0 XA + PB0XB
         (PTOTAL) = PA0 XA + PB0(1—XA) ,  600 = 450 x XA + 700(1—XA),   XA = 0.40  and XB = 0.60
          PA = PA0 XA = 450 x 0.40 = 180 mm of Hg,  PB = PB0XB = 700 X 0.60 = 420 mm of Hg
XA in vapour phase = partial pressure of A / Total vapourpressure(PA + PB) = 180/ 180 + 420 = 0.30
           XB in vapour phase = 1—0.30 = 0.70
8
   NCERT page 60 (2.6) ans—158.7ml ,
mass of mixture = 1gm , let Na2CO3 = x gm,  mass of NaHCO3 = 1—x , moles of Na2CO3 = x / 106.
            Moles of NaHCO3 = 1—x / 84.   equivimolar mixture means  x/106 = 1—x / 84.  x = 0.557
           Mass of Na2CO3 = 0.557gm, mass of NaHCO3 = 1—0.557 = 0.443gm.
           Na2CO3     +   2 HCl           2 NaCl+  H2O    +    CO2
           106gm            2x36.5=73                106 gm  Na2CO3need  = 73gm HCl
                                                                    0.557gm will need       = 73 x 0.557 / 106 =0.384gm HCl
           Similarly—
             NaHCO3   +   HCl               NaCl+  CO2   +  H2O
            84gm               36.5gm                    84gm   NaHCO3 need = 36.5gm HCl
                                                                    0.443 will need            = 36.5x 0.443 / 84 = 0.192gm HCl
                                                                   Total HCl used = 0.384 + 0.192 = 0.576gm
MHCl=  moles of HCl / vol in L
0.576/ 36.5
0.1 =  — -------- ,    v =   0.157 Litre(answer)
V in L
9

 Kf x WB x 1000                                  Kf x WB x 1000
 NCERT page 60(2.21), For AB2,  ∆Tf = ---------------------- ,    For AB4 , ∆Tf = -------------------
MB x WA                                                                MB x WA
                                                                            5.1 x 1 x 1000                                    5.1 x 1 x 1000                                     
                                                                 2.3 = --------------------- ,                     1.3 = -------------------
                                                                               MB x 20                                             MB x 20
MB = 110.86                                          MB = 196.15
       AB2 = A  +  2B = 110.86,            AB4 =  A  + 4B  =  196.15,  solve equations and find A & B values
      A  =  25.58,  B  = 42.64 (ans)
10
 NCERT page 61(2.32) Molar mass of CH3CH2CHClCOOH = 122.5,
        moles of CH3CH2CHClCOOH= 10/122.5 = 0.0816, m = 0.0816/ 0.250kg = 0.3264
                     α = √ Ka/C = √ 1.4 x 10—3/ 0.3264 = 0.065,            i—1                    i—1        i—1
                                                                                              α = --------,  0.065 = -------- = -------,  i = 1.065
                                                                                                      m—1                  2—1        1
                  ∆Tf = i x Kf x m = 1.065 x 1.86 x 0.3264 = 0.650 (ANS)


HINDI



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Ø कीसी भी दो वर्त्तमान समस्याओ पर निबंध लिखीए |
Ø जनसंचार माध्यम से १० प्रश्न उत्तर लिखीए |
Ø किसी एक विषय पर फिचर लेखन लिखिए |
Ø कक्षा में दिए गये पूर्व प्रश्नपत्र हल करे |
Ø पाठ्यक्रम पुनरावृत्ति करे |

BIOLOGY 



1.       Completion of practical record.
2.        As per Theory chapters 5, 8, and 13 write comments with neat labeled diagram on Pedigree analysis, amoebiosis, ascariasis and adaptive features of an aquatic plant (Hydrilla/lotus) an aquatic animal (Marine/fresh water fish),  Any One desert plant and one desert animal in practical record.
3.       Preparation of chapter 1 to 5 for the board examination thoughrly with the help of NCERT text book.  Write point wise notes. No details required
4.       Diagram practice and schematic representation from Chapter 1 to 6.
5.       Investigatory project work allotted chapter wise 1 to 16 as per the student’s own choice.
6.       Solve Two CBSE sample paper’s questions of chapter 1 to 5.
7.       Write abbreviations from biology text-book(approx 100 abbreviations)
8.       Write 25 common microbes with their scientific name and their diseases.



CLASS-XII (MATHEMATICS)

SUMMER VACATION HOME WORK AND ASSIGNMENT
1.       Chapter-2: Inverse trigonometric functions
2.       Chapter-3: Matrices
3.       Chapter-4: Determinants
4.       Chapter-5: Continuity And Differentiation
5.       Chapter-6: Application of differentiation (Exercise 6.1, Exercise6.2, Exercise 6.3 and Exercise 6.5)
Note: Solve all the questions of exercises with examples
  




 






1 comment:

  1. In most of the world, summer is associated with sun, sand, and beaches. Finish your home work and plan holiday with your family.

    ReplyDelete