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)

Wednesday, August 08, 2012

Quantum number combination Class XI (CBSE/ISC/WB)




n


l


m
Subshell
Number of orbitals in Subshell
Maximum number of electrons required to fill the subshell
Total numbe

r of electrons in one subshell
1
0
0
1s
1
2
2







2
0
0
2s
1
2

2
1
1,0,-1
2p
3
6
8







3
0
0
3s
1
2

3
1
1,0,-1
3p
3
6

3
2
2,1,0,-1,-2
3d
5
10
18







4
0
0
4s
1
2

4
1
-1,0,1
4p
3
6

4
2
-2,-1,0,1,2
4d
5
10

4
3
-3,-2,-1,0,1,2,3
4f
7
14
32

Thursday, August 02, 2012

Mole calculations (Chemistry) Class XI All Boards (CBSE/ISC/WB etc)




Mole calculations for practice
Class: XI                                                                      Subject: Chemistry
Total Marks: 10                                                           

1.                  The atomic mass of Na is 23. Find the mass of 1 Na atom?
2.                  How many moles are present in 11.2 liters of O2 under normal conditions?
3.                  Convert 64g of O2 gas in moles.
4.                  Convert 54g of H2O in moles.
5.                  How many moles are present in 44.8 liters of Cl2 gas under normal conditions?
6.                  What volume does 44g of CO2 at STP occupy?
7.                  What is the mass of 2 mol of H2SO4?
8.                  How many molecules of H2O are present in 36g of water?
9.                  How many molecules are there in 21.6g of CH4?
10.              What will be the weight of 1 mole of CuBr in gram?


ANSWERS:
  1. 3.82 x 10-23
  2. 0.5 moles
  3. 2.0 moles
  4. 3.0 moles
  5. 2.0 moles
  6. 22.4 liters
  7. 196g
  8. 1.2 x 1024
  9. 8.13 x 1023
  10. 71.2