1. Valency of an element X is 3. Write the chemical formula of its oxide.
2. What is negative work?
3. Why do we keep both snake and turtle in the same class?
4. Why is sound wave is called a longitudinal wave?
5. Describe the microscopic structure of the cell?
6. A sound wave has a frequency 2Hz and wave length 40 cm. How long will it take to travel
1.6 Km.
7. Define potential energy, what are the different types of potential energy?
8. Compare the properties of electron, proton and neutron?9. Write the characteristics of kingdom animalia.
10. Sound waves of wave length X travel from a medium in which velocity is V m/s into
another medium in which if velocity is 3 m/s is the wavelength of sound in the second
medium.
11. Why do you fall in the forward direction when a moving bus brakes to a stop and fall
backward when it accelerates from rest.
12. Write a method to separate different gases of air.
13. Classify each of the following as a physical or chemical change. Give reasons.
a. Drying of a shirt in the sun.
b. Rising of hot air over a radiator.
c. Buring of kerosene in a lantern.
d. Change in the colour of black tea on adding lemon juice in it.
14. State Newton's second law of motion and derive it mathematically?
15. Raghu switched from traditional to modern farming practices in which he used large
amount of fertilizers and pesticide to gain an increase in profit.
i. What are the adverse effect of modern farming?
ii. What is soil pollution?
iii. What do you think will be effect of modern farming?
iv. What alternative method could be more beneficial for farming?
16. Why does the temperature of a substance remain constant during the melting point or
boiling point?
17. Draw a plant cell and label the parts.
a. synthesize food
b. Produce energy
c. Store house of organic substance like protein organic acids.
d. Packages material coming from endoplasmic reticulum.
e. Determine function and development of cell?
18. a. What happen to sugar when it is dissolved in water? Where does the sugar go? What
information do you get about the nature of matter from the dis solution of sugar in
wale.
b. Which type of compounds can be purified by sublimation?
19. a. State two basis of classifying plants and animals into different categories.
b. List three characteristics features of fungi?c. Some fungal species live in permanent mutually dependent relationship with
cynobacteria?
20. What do you mean by work? Give an example of negative work done? What is the work
to be done to increase the velocity from 18 km/hr to 19 km/hr if the mass of the care is
2000 kg.
21. "Soil is formed by water". If you agree to this statement then give reasons for you
answers.
Section 'B'
22. Which would require a greater force accelerating a 2 kg mass at 5 ms
-2 or a 4 kg mass at 2
ms
-2
?
23. In experiment to demonstrate the boiling point of water. state reason for following
precautions.
a. The bulb of thermometer should not touch the sides of the beaker?
b. Pumice stone should be added while boiling water.
24. Seena was asked to prepare four separate mixtures in four beakers A, B, C, D by mixing
sugar, fne sand, thin paste of starch and chalk powder respectively in water and then
categories each as stable or unstable what will be the correct categorization?
25. A baby is not able to tell her/his caretakers that she/he is sick. What would help us to find
out that the baby is sick?
26. A free falling object eventually stops on reaching the ground. What happens to its kinetic
energy.
27. A sound wave travels at a speed of 340 m/s. If the wave length of wave is 1.4 Km. What is
the frequency of the wave?
Answers
Answered by
57
Answer:
Changes that involve that formation of new substance are called chemical change.
There may be change in colour
A precipitate may be formed.
Heat may be given out or absorbed
Answered by
41
Answer:
all living organism are grouped into plants and animals on the basis of their common caracteres.
environment consists of living and nonliving.
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