CBSE Guess > Papers > Important Questions > Class XII > 2009 > Science > Science By Vivek Soni
CBSE CLASS XII
Section - A (Physics)
Q. 1. Derive the first equation of motion graphically. [2]
Q. 2. “Still friction is essential , although it is useful in many ways.” Comment. [2]
Q. 3. A train is traveling at a speed of 50 Km/hr. Breaks are applied so as to produce the uniform acceleration of - 0.5 m/s2. Find how far the train will go before it is brought to rest. [2]
Q. 4. An object of mass 1 Kg traveling in a straight line with a velocity of 10 m/s collides with and sticks to a stationary wooden block of mass 5 Kg.Then they both move off together in the same straight line.Calculate the total momentum Just before and after the impact.Also calculate the velocity of the combined object. [3]
Q. 5. (a) What can you say about the motion of an object whose distance time graph is parallel to time axis ?
(b) How will you calculate the distance traveled by an object with the help of speed time graph. [3]
Q. 6. Differentiate between speed and velocity . [3]
Q. 7. Give the answer of following in one word or in one sentence : - [5]
- Give one example of retardation.
- Under which condition velocity varies with time but the velocity of an object during any time interval is not zero.
- What is inertia ?
- State one method used to reduce the friction between two surface.
- Define the S.I unit of force.
Or
Prove that total momentum of an object before and after the collision remains the same.
Section - B (Chemistry)
Q. 8. Give four examples of a substance which are sublime in nature. [2]
Q. 9. Why is the rate of diffusion in liquid is higher then that of solid ? [2]
Q. 10. Why is the solid Carbondioxide also known as Dry ice ? [2]
Q. 11. Give examples of following types of collides : [3]
- Liquid into gas.
- Solid into liquid.
- Gas into solid.
Q. 12. What is chromatography ? Hence describe an activity to show it ? [3]
Q. 13. Give reasons for the following : [3]
- Ice at 273 K is more effective in cooling than water at same temperature.
- A desert cooler cools better on a hot dry day.
Q. 14. List out the difference between three states of matter. [5]
Or
Differentiate between Solution, Suspension and Colloidal Solution.
SECTION – C (Biology)
Q. 15. Who coined the term cell and when? [1]
Q. 16. What is Plasmolysis ? [1]
Q. 17. What is diffusion. Explain how it is useful for living beings. [3]
Or
Give reasons for the following :
- Mitochondria is known as powerhouse of cell.
- Lysosomes are also known as suicide bags.
Q. 18. Using appropriate diagram, list out the difference between plant cell and the animal cell.
Or
What is a plasma membrane? Write its main feature? Why is plasma membrane called a selectively permeable membrane? [5]
Paper By Vivek Soni
