Wednesday, February 27, 2013

Human Eye and Colourful World (CBSE) Class X (Physics)


HUMAN EYE AND COLOURFUL WORLD
(Each question is of 2 marks)
Class X (CBSE) Physics

1.      Why when the sun is overheated at noon, it appears white but when the same sun is near the horizon at sunset, it appears red?
2.      Why stars twinkle at night?
3.      Why ocean is blue in colour?
4.      When we enter the dim light room from bright sunlight outside, why does it take time to see the objects clearly?
5.      How rainbow is formed?
6.      A boy uses spectacles of focal length 50cm. name the defect of vision he is suffering from.
7.      A man can read the number of distant bus clearly but he finds difficulty in reading book. What disease he is having?
8.      Astronauts observe the sky as dark instead of blue why?
9.      Why planets do not twinkle?
10.  Why is a normal eye not able to see clearly the objects placed closer than 25cm.

Tuesday, February 26, 2013

Heredity and Evolution (Class X) CBSE test paper




Heredity and Evolution
(All questions are of 1 mark)

1.      What are fossils?
2.      What is monohybrid cross?]
3.      Give two examples of analogous organs.
4.      What are vestigial organs?
5.      What are dominant genes?
6.      Define the term evolution.
7.      What is scientific name of Human Beings?
8.      What are allosomes?
9.      Write the scientific term used for ‘Science of Heredity and variation’.
10.  Radish and carrot are homologous or analogous structures?
11.  Write the name of different types of possible blood groups?
12.  Define F1 generation.
13.  What will be the sex of the embryo if an egg is fertilized by the sperm having 22+y composition?
14.  What is dihybrid cross?
15.  Define the term progeny.

Test paper on Periodic classification of the elements (X) CBSE


Periodic classification of the elements.
(CBSE) Class X Test

1. Write electronic configuration of C and Na.  (1)
2. The atom of an electronic configuration 2 8 8 2 belongs to which period? (1)
3. Which is more reactive F or Cl?  (1)
4. Which is bigger in size Cl/Cl- ? (1)
5. Define the law of Octaves? (2)
6. Why elements of a same group show same valency? (2)
7. Discuss the position of H atom in a periodic table. (2)
8. Differentiate metals and non metals? (2)
9. Define modern periodic law. (2)
10.What are metalloids? Explain with example. (2)



Tuesday, February 19, 2013

Lewis structures of chemical compound

Draw Lewis Structure of following

1. NH3
2. CO
3. CO2
4. CH4
5. HNO3
6. HCl

Friday, February 15, 2013

Chemistry (Class X)(CBSE) Second term test paper on periodic classification of elements)


Class X (CBSE)

Second Term
 

PERIODIC CLASSIFICATION OF ELEMENTS:

 

Note: Question 1-3 are 1 mark each, Questions 4-10 are 2 marks each.

 

1.      What is general trend in atomic size as you move from left to right in a period?

2.      Why all the atoms of a period have different chemical properties?

3.      How many electrons are present in valence shell of Cl?

4.      What are the limitations of Dobernier’s classification?

5.      What are noble gases? Explain their characteristics?

6.      Write the electronic configuration of Na, O, F and C.

7.      Explain out of ‘Na’ and ‘K’ who is more electropositive in nature?

8.      Why atomic number of an element is more important than its mass number?

9.      Compare Na and K with respect to their valence, formula of their oxide and formula of their chloride.

10.  Atomic number of an element X is 17. Predict its valence and tell whether it is metal or non metal?

Wednesday, February 13, 2013

CBSE X (Chemistry) Second term (Test paper)


Class X
Second term
Unit: Chemical Substances –Nature and Behaviour
CARBON COMPOUNDS

(Question 1-10 are 1 Mark, Question 11-14 are 2 Marks and Question 15-18 are 3 Marks)
1.       Name the following functional group.  (–OH, -COOH)
2.       Give electron dot structure of CH3Cl.
3.       Write formula of methanol.
4.       Draw structure of Chlorobutane.
5.       What are oxidizing agents?
6.       Name the functional group present in the compound               CH3CH2NH2.
7.       What is the odour of the acetic acid like?
8.       Name the CH3C=CH.
9.       How many C-H bonds are present in ethane C2H6.
10.   What is the need to denature alcohol?
11.   Give one example of substitution reaction.
12.   Draw structural formula of all isomers of hexane.
13.   Write chemical equation showing decarboxylation reaction of ethanoic acid.
14.   What are enzymes? Name the enzyme which ferments sugar cane to ethanol?
15.   What are synthetic detergents? Give example and how it is better than soap?
16.   What is homologous series? Explain with example. By how many carbon atoms and hydrogen atoms do any two adjacent homologues differ?
17.   What are esters? Write chemical equation showing formation of ester?
18.   Write  the reaction and name the products formed.
a)      Acetic acid and sodium hydroxide are heated together.
b)      Ethanol is burnt in oxygen in the presence of alkaline KMnO4
   


Monday, February 11, 2013

Compound interest

Compound Interest
 (i)                  Find the amount and the 
             compound interest on 8000 
              at 5% p.a for 2 years.

Principal = Rs 8000/-

Rate of Interest = 5% p.a

Interest for the first year 

= 8000 x 5% x 1/100 = Rs 400
                                  
                 Amount for the first year or 
                  principal for the second year

                              = (8000 + 400) Rs = 8400 Rs
   
Interest for the second year 

= 8400 x 5% x 1/100 = Rs 420

                               Amount for the second year

                              =  (8400 + 420) Rs = 8820 Rs

                              Total Compound Interest
                              = 8820 – 8000 Rs = Rs 820  

Thursday, February 07, 2013

chemistry test paper (XII) Amines, biomolecules, polymers, chemistry in every day life

TEST PAPER-CHEMISTRY
CLASS-XII
1.    Draw resonance structures of Aniline?
2.    Write Hoffman elemination reaction?
3.    Draw D-Glucose?
4.    What is muta – rotation?
5.    Explain tertiary structure of Proteins?
6.    Write defination of Enzyme?
7.    Write difference between Fibrous proteins and Globulor Proteins?
8.    Write  structure of Nylon-6?
9.    Define polymerisation?
10.  What is denaturation of portein?
11.  What is Condensation Polymerisation?
12.  What are antacids?
13.  What is Hard Water?
14.  Draw Structure of Zwitter-ion from of alpha amino acetic acid?
15.  What is translation?

Saturday, January 19, 2013

If you want to solve chemistry final papers chemistry XII (CBSE) paper. Leave message or comment for sample papers.

Wednesday, January 09, 2013

Molecular Mass calculations

CALCULATE THE MOLECULAR MASS
S. No
Compound
Molecular mass
1.
AgCl

2.
Na2CO3

3.
H2SO4

4.
HCl

5.
CuSO4.7H2O

6.
HNO3

7.
KMnO4

8.
B2H6

9.
CaCl2

10
Ca(OH)2


Sunday, December 02, 2012

Test Chapter: Sound (ICSE) (Physics)

Class : X
Board: ICSE
Chapter: Sound
Subject :Physics

1. What is an echo?
2. Give relation between frequency, velocity and wavelength.
3. Give two differences between free vibrations and damped vibrations?
4. name three factors on which the frequency of vibration of stretched string depends.
5. Why when a troop crosses a suspension bridge, the soldiers are asked to break steps.
6. Why are the stringed instruments provided with a sound box?
7. Define pitch. Draw wave of different pitches.
8. Differentiate between musical note and a pitch.
9. How is it possible to detect the filling of a bottle under a water tap by hearing the sound at a distance.
10. What is the safe limit of sound level in dB for our ears?

Tuesday, November 20, 2012

Test (Organic chemistry) (ICSE) Class X




Class:  X                                                                                Chapter : Organic chemistry
Subject: Chemistry                                                                  Board: ICSE
Marks: 20

  1. Write classification of Hydrocarbons. (2)
  2. Explain the phenomenon of isomerism with example. (2)
  3. Explain Homologous series with example. (2)
  4. Write general formula of alkane, alkene and alkynes. (2)
  5. Write two chemical properties of methane. (2)
  6. Convert ethane into ethyl alcohol. (2)
  7. Write reaction showing halogenation. (2)
  8. What is polymerization? (2)
  9. Write reaction of acetic acid with sodium hydroxide. (2)
  10. Write two main uses of acetic acid. (2)

Thursday, August 30, 2012

Test Current Electricity (Physics) (ICSE) X


Test Current Electricity (ICSE)

Subject: Physics                                                            Total Marks: 11
Class: X                                                                       Max time: 20min

  1. Define emf of a cell. (1)
  2. Draw a diagram showing free fall of a body. (1)
  3. Show a series combination of a resistance in diagrammatic form. (1)
  4. Calculate the resistance of 1.5km long copper wire of radius 2mm. The resistivity of copper is 1.72 × 10-8 Ωm. (2)
  5. State Ohm’s law. Write the conditions for Ohm’s law. (2)
  6. Define potential difference and give it’s units. (2)
  7. Write the formula of series and parallel combination of resistance. (2)



Friday, August 24, 2012

Test Chapter ATOMIC STRUCTURE Class XI (Chemistry) CBSE/WB/ISC



Test Chapter ATOMIC STRUCTURE

Subject: Chemistry                                                        Total Marks: 25
Class: XI                                                                      Max time: 60 minutes

  1. Write the difference between emission spectrum and absorption spectrum. (1)
  2. Why the energy of electron in an atom is negative?                                      (1)
  3. What is Hund’s rule of maximum multiplicity? Explain with examples.     (1)
  4. Two electrons occupy the same orbital together despite the repulsions of like electrostatic charges.                                                                                             (1)
  5. Write the complete symbol for the atom with the given atomic number
(Z) and atomic mass (A).
(a)    Z = 17  A = 35
(b)   Z = 4    A = 9                                                                           (1)
6.  Which of the following ions are unlikely and Why? K+ and I3-                 (1)
7.  Explain why the electronic configuration of Cr is [Ar] 3d54s1
and not [Ar] 3d44s2                                                                                (1)
8. State Pauli’s exclusion principle.                                                                (1)
9.  Calculate the total number of electrons present in 2g of CH4.                     (2)
10. Write the differences between cathode rays and anode rays.                     (2)
11. Calculate the wave number of the line of frequency 4 x 1014  s-1                (2)
12. Write the main postulates of Planck’s Quantum theory.                             (2)
13. If the velocity of electron in Bohr’s first orbit is 2.19 x 108 m/s.
Calculate the de- Broglie wavelength associated with it.                             (2)
14. Explain line spectrum of Hydrogen.                                                           (2)
15. Using s, p, d notations, describe the orbital with the following
quantum numbers.
                 a) n = 1, l = 0
                 b) n = 3, l = 1
                 c) n = 4, l = 2
                 d) n = 4, l = 3                                                                                  (2)                               
16. (i) An atomic orbital has n = 3. What are possible values of l and ml ?
     (ii) List the quantum numbers (ml and l) of electrons for 3d orbital.              (3)
     (iii) Which of the following orbitals are possible?
                             1p, 2s, 2p and 3f



Wednesday, August 22, 2012

Test (Physics) Class X Chapter Refraction of light through plane surfaces



Subject: Physics                        Class: X
Board: ICSE                            Max Marks: 16
Time: 35min
Chapter: Refraction of light through a plane surfaces.


  1. What causes refraction? (1)
  2. The refractive index of water with respect to air is 4/3. What is the refractive index of air with respect to water? (1)
  3. Write Snell’s Law? (2)
  4. Name the factors affecting the angle of deviation? (2)
  5. Draw a diagram showing the bending of stick due to refraction. (2)
  6. Write differences between total internal reflection and simple reflection from a plane mirror. (2)
  7. Show erecting of image in a total reflecting prism? (2)
  8. Why a crack in a vessel often shines like a mirror? (2)
  9. Explain a mirage? (2)

Tuesday, August 21, 2012

Test Chapter (Thermodynamics) Physics XI Board CBSE




Class: 11th                                                                                           Subject: Physics
Chapter: Thermodynamics                                                                   Total Marks: 21

  1. A one liter flask contains some mercury. It is found that at different temperatures, the volume of air inside the flask remains the same. What is the volume of mercury in the flask? Given the co-efficient of linear expansion of glass = 9 × 10-6 / 0C and co-efficient of volume expansion of mercury = 1.8 × 10-4 / 0C.                                                                     (2)
  2. The resistance of certain platinum resistance thermometer is found to be 2.56 Ω at 00C and 3.56 Ω at 1000C. When the thermometer is immersed in a given liquid, its resistance is observed to be 5.06 Ω. Determine the temperature of liquid?                                                                 (2)
  3. A ball is dropped on a floor from a height of 2cm. After the collision, it rises up to a height of 1.5m. Assuming that 40% of mechanical energy lost goes to thermal energy into the ball. Calculate the rise in temperature of the ball in the collision. Specific heat capacity of the ball is 800J/K. Take g = 10m/s2                                                                                                      (2)
  4. What is critical temperature? How will you differentiate between a gas and a vapour depending on critical temperature?                (2)
  5. A 50g lead bullet, specific heat 0.02 cal/g/0C is initially at 300C. It is fixed vertically upward with a speed of 840m/s and on returning to the starting level strikes a cake of ice at 00C. How much ice is melted? Assume that all energy is spent in melting ice only?                         (2)
  6. The tile floor feels colder than the wooden floor even though both floor materials are at same temperature. Why?                                 (2)
  7. How does second law of thermodynamics explain expansion of gas? (2)
  8. One kilogram molecule of a gas at 400K expands isothermally until its volume is doubled. Find the amount of work done and heat produced? (2)
  9. Why does absolute zero not correspond to zero energy?                (2)
  10. Calculate the work done during the isothermal Process?                (3)








Test Chapter (Motion in plane) Physics XI CBSE Board



Test Chapter MOTION IN PLANE

Subject: Physics                                                            Total Marks: 20
Class: XI                                                                      Max time: 30 minutes

1.         What is the direction of centripetal force when particle is following a circular path?                                                                                                                     (1)
2.         Write differences between scalars and vectors.                                      (1)
3.         Draw displacement time graph for constant velocity and at zero velocity.            (1)
4.         Define unit vector and null vector.                                                                      (1)
5.         What is the angle between two forces of 2N and 3N having resultant 4N.          (2)
6.         At what range will a radar set show a fighter plane flying at 4 km above its centre and at distance of 6 km from it?                                                             (2)
7.         A cricketer hits a cricket ball straight up into the air. The cricket ball has an initial velocity of 20 m·s−1.
(a)        What height does the ball reach before it stops to fall back to the ground?
(b)        How long has the ball been in the air for?                                               (2)
8.         A ball is thrown vertically upwards and then it returns to the thrower. Is it a projectile? Explain?
Draw trajectory of projectile motion of soccer ball being kicked.                       (2)
9.         Pick out the only vector quantity in the following list: Temperature, pressure, impulse, time, power, total path length, energy, gravitational potential, coefficient of friction, charge.                                                                   (2)
10.       What is a uniform circular motion? Explain the terms time period, frequency and angular velocity. Establish relation between them.                                      (3)
11.       (a) Define time of flight and horizontal range?
(b) From a certain height above the ground a stone A is dropped gently.
Simultaneously another stone B is fired horizontally. Which of the two stones will arrive on the ground earlier?                                                                (3)