Sample Paper II

Question 1. Which among the following statement(s) is(are) true? Silver chloride on exposure to sunlight for long duration turns grey due to

(i) the formation of silver by decomposition of silver chloride

(ii) sublimation of silver chloride

(iii) decomposition of chlorine gas from silver chloride

(iv) oxidation of silver chloride

(a) (i) only

(b) (i) and (iii)

(c) (ii) and (iii)

(d) (iv) only

Question 2. Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam?

(a) FeO

(b) Fe$_{2}$O$_{3}$

(c) Fe$_{3}$O$_{4}$

(d) Fe$_{2}$O$_{3}$ and Fe$_{3}$O$_{4}$

Question 3. CH$_{3}$ CH$_{2}$ OH $\xrightarrow{\text{AlkalineKMnO}_{4} \text{ +Heat}}$ CH$_{3}$ COOH In the above given reaction, alkaline KMnO$_{4}$ acts as

(a) reducing agent

(b) oxidising agent

(c) reducing as well as oxidising agent

(d) dehydrating agent

Question 4. Which of the following gives the correct increasing order of the atomic radii of O, F and N?

(a) O, F, N

(b) N, O, F

(c) O, N, F

(d) F, O, N

Question 5. Which of the following statement(s) is(are) true about heart?

(i) Left atrium receives oxygenated blood from different parts of the body while right atrium receives deoxygenated blood from lungs

(ii) Left ventricle pumps oxygenated blood to different body parts while right ventricle pumps deoxygenated blood to lungs

(iii) Left atrium transfers oxygenated blood to right ventricle which sends it to different parts of the body

(iv) Right atrium receives deoxygenated blood from different parts of the body while left ventricle pumps oxygenated blood to different parts of the body

(a) (i)

(b) (ii)

(c) (ii) and (iv)

(d) (i) and (iii)

Question 6. The substance that triggers the fall of mature leaves and fruits from plants is

(a) Auxin

(b) Gibberellin

(c) Abscisic acid

(d) Cytokinin

Question 7. Which among the following statements are true for unisexual flowers?

(i) They possess both stamen and pistil

(ii) They possess either stamen or pistil

(iii) They exhibit cross pollination

(iv) Unisexual flowers possessing only stamens cannot produce fruits

(a) (i) and (iv)

(b) (ii), (iii) and (iv)

(c) (iii) and (iv)

(d) (i), (iii) and (iv)

Question 8. According to the evolutionary theory, formation of a new species is generally due to

(a) sudden creation by nature

(b) accumulation of variations over several generations

(c) clones formed during asexual reproduction

(d) movement of individuals from one habitat to another

Question 9. Under which of the following conditions the real image formed by a concave mirror is larger than the actual object?

(a) When source is at a distance equal to radius of curvature of the concave mirror

(b) When source is at a distance less than the focal length of the concave mirror

(c) When source is placed at a distance between the focus and centre of curvature of the concave mirror

(d) When source is placed at a distance greater than the radius of curvature of the concave mirror

Question 10. The path of a ray of light passing through a rectangular glass slab tested by four students are shown in Figure as A, B, C and D. Which one of them is correct?

(a) A

(b) B

(c) C

(d) D

Question 11. In the following given circuits, heat produced in the resistor or combination of resistors connected to a 12 V battery will be

(a) same in all the cases.

(b) minimum in case (i).

(c) maximum in case (ii).

(d) maximum in case (iii).

Question 12. What is the maximum resistance which can be made using five resistors each of $1/5 \, \Omega$?

(a) $1/5 \, \Omega$

(b) $10 \, \Omega$

(c) $5 \, \Omega$

(d) $1 \, \Omega$

Question 13. In an electrical circuit three incandescent bulbs A, B and C of rating 40 W, 60 W and 100 W are connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness?

(a) Brightness of all the bulbs will be the same

(b) Brightness of bulb A will be the maximum

(c) Brightness of bulb B will be more than that of A

(d) Brightness of bulb C will be less than that of B

Question 14. Choose the incorrect statement

(a) Fleming’s right-hand rule is a simple rule to know the direction of induced current

(b) The right-hand thumb rule is used to find the direction of magnetic fields due to current carrying conductors

(c) The difference between the direct and alternating currents is that the direct current always flows in one direction, whereas the alternating current reverses its direction periodically

(d) In India the AC changes direction after every $\frac{1}{50}$ second

Question 15. Among the statements given below select the ones that describe the concept of sustainable development

(i) Planned growth with minimum damage to the environment

(ii) Growth irrespective of the extent of damage caused to the environment

(iii) Stopping all developmental work to conserve the environment

(iv) Growth that is acceptable to all the stakeholders

(a) (i) and (iv)

(b) (ii) and (iii)

(c) (ii) and (iv)

(d) (iii) only

Question 16. Identify the oxidising agent (oxidant) in the following reactions

(a) Pb$_{3}$O$_{4}$ + 8HCl $\rightarrow$ 3PbCl$_{2}$ + Cl$_{2}$ + 4H$_{2}$O

(b) Mg + 2H$_{2}$O $\rightarrow$ Mg (OH)$_{2}$ + H$_{2}$

(c) CuSO$_{4}$ + Zn $\rightarrow$ Cu + ZnSO$_{4}$

(d) V$_{2}$O$_{5}$ + 5Ca $\rightarrow$ 2V + 5CaO

Question 17. A non-metal A is an important constituent of our food and forms two oxides B and C. Oxide B is toxic whereas C causes global warming

(a) Identify A, B and C

(b) To which Group of periodic table A belongs?

Question 18. Atomic number of a few elements are given below

(i) 10

(ii) 20

(iii) 7

(iv) 14

(a) Identify the elements

(b) Identify the period to which these elements belong

Question 19. What will happen if the mucus is not secreted by the gastric glands?

Question 20. Name the plant hormones responsible for the following

(a) elongation of cells

(b) growth of stem

(c) promotion of cell division

(d) falling of senescent leaves

Question 21. How are general growth and sexual maturation different from each other?

Question 22. A very small population of a species faces a greater threat of extinction. Provide a suitable genetic explanation.

Question 23. It is established that an electric current through a metallic conductor produces a magnetic field around it. Is there a similar magnetic field produced around a thin beam of moving (i) positively charged alpha particles, (ii) neutrons? Justify your answer by giving suitable arguments.

Question 24. A child has drawn the electric circuit to study Ohm’s law as shown in the figure. His teacher told that the circuit diagram needs correction.

Study the circuit diagram and redraw it after making all corrections.

Question 25. Three $2 \, \Omega$ resistors, A, B, and C, are connected as shown below. Each of them dissipates and can stand a maximum power of 18 W without melting. Find the maximum current that can flow through the three resistors.

Question 26. Draw the reflected ray corresponding to the ray incident on a concave mirror as shown in the ray diagram?

Question 27. Why does a light ray incident on a rectangular glass slab immersed in any medium emerge parallel to itself? Explain using a diagram.

Question 28. A person needs a lens of power –4.5 D for correction of her vision.

(a) What kind of defect in vision is she suffering from?

(b) What is the focal length of the corrective lens?

(c) What is the nature of the corrective lens?

Question 29. In a village in Karnataka, people started cultivating crops all around a lake which was always filled with water. They added fertilisers to their field in order to enhance the yield. Soon they discovered that the waterbody was completely covered with green floating plants and fish in the lake started dying in large numbers.

Analyse the situation and give reasons for excessive growth of plants and death of fishes in the lake.

Question 30. Although coal and petroleum are produced by degradatioin of bio- mass, yet we need to conserve them. Why?

Question 31. In the following s c h e m a t i c diagram for the preparation of hydrogen gas as shown in Figure, what would happen if following changes are made?

(a) In place of Zn g r a n u l e s , same amount of zinc dust is taken in the test tube

(b) Instead of dilute sulphuric acid, dilute hydrochloric acid is taken

(c) In place of Zn, Cu turnings are taken

(d) Sodium hydroxide is taken in place of sulphuric acid and tube is heated

or

A metal carbonate X on reacting with an acid gives a gas which when passed through a solution Y gives the carbonate back. On the other hand, a gas G that is obtained at anode during electrolysis of brine is passed on dry Y, it gives a compound Z, used for disinfecting drinking water. Identity X, Y, G and Z. Also, write the chemical reactions involved.

Question 32. When ethanoic acid reacts with sodium hydrogencarbonate, a salt X is formed and a gas Y is evolved.

(a) Identify X and Y. Write chemical equation of reaction involved.

(b) Describe an activity and draw the diagram of the apparatus to prove that the evolved gas is the one which you have named.

or

Look at Figure and answer the following questions.

(a) What change would you observe in tube B containing calcium hydroxide solution

(b) Write the reaction involved in test tubes A and B respectively

(c) If ethanol is given instead of acetic acid, would you expect the same change?

(d) How can a solution of lime water be prepared in the laboratory?

Question 33. When do we consider a person to be myopic or hypermetropic? Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?

or

Explain the refraction of light through a triangular glass prism using a labelled ray diagram. Hence define the angle of deviation.

Question 34. How can solar energy be harnessed? What are the limitations in using solar energy? How are these limitations overcome?

or

What is biomass? Explain the principle and working of a biogas plant using a labelled schematic diagram

Question 35. Explain with the help of a labelled diagram the distribution of a magnetic field due to a current through a circular loop. Why is it that if a current carrying loop has n turns the field produced at any point is n times as large as that produced by a single turn?

or

Explain the phenomenon of electromagnetic induction? Describe an appropriate experiment to show that a current is set up in a closed loop when an external magnetic field passing through the loop increases or decreases.

Question 36. Suggest any five activities in daily life which are eco-friendly.

or

Explain some harmful effects of agricultural practices on the environment.