ExamFusion

India

SCIENCE BRAHMASTRA TEST

Class 10 - Science
Time Allowed: 3 hours Maximum Marks: 80

Section A
1. Which of the statements about the reaction below are incorrect? [1]
2PbO(s) + C(s) → 2Pb(s) + CO2(g)

a. Lead is getting reduced.

b. Carbon dioxide is getting oxidised.
c. Carbon is getting oxidized.
d. Lead oxide is getting reduced.

a) All of these b) (a) and (c)

c) (a) and (b) d) (a), (b) and (c)

2. A solution turns red litmus blue, its pH is likely to be [1]

a) 4 b) 1

c) 10 d) 5
3. A solution reacts with crushed egg shells to give a gas that turns lime water milky. The solution contains [1]

a) LiCl b) KCl

c) HCl d) NaCl
4. Which of the following pairs will give displacement reactions? [1]

a) FeSO4 solution and silver metal b) AgNO3 solution and copper metal

c) NaCl solution and copper metal d) MgCl2 solution and aluminum metal

5. Which of the following methods is suitable for preventing an iron frying pan from rusting? [1]

a) Applying paint b) Applying a coating of zinc

c) Applying grease d) All of these

6. While cooking if the bottom of the vessel is getting blackened on the outside, it means that: [1]

a) The fuel is burning completely. b) The food is not cooked completely.

c) The fuel is not burning completely. d) The fuel is wet.

7. The kidneys in human beings are a part of the system for [1]

a) respiration b) excretion

c) nutrition d) transportation
8. The xylem in plants are responsible for: [1]

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 a) transport of amino acids b) transport of oxygen

c) transport of food d) transport of water

9. The autotrophic mode of nutrition requires [1]

a) Sunlight b) Carbon- dioxide and water

c) All of these d) Chlorophyll

10. The breakdown of pyruvate to give carbon dioxide, water and energy takes place in: [1]

a) mitochondria b) chloroplast

c) cytoplasm d) nucleus
11. Which of the following is a plant hormone? [1]

a) Oestrogen b) Thyroxin

c) Insulin d) Cytokinin
12. The gap between two neurons is called a: [1]

a) impulse b) dendrite

c) axon d) synapse
13. The brain is responsible for: [1]

a) thinking b) balancing the body

c) regulating the heartbeat d) All of these

14. The human eye can focus on objects at different distances by adjusting the focal length of the eye lens. This is [1]
due to

a) Presbyopia b) Near-sightedness

c) Accommodation d) Far-sightedness
15. An electron enters a magnetic field at right angles to it, as shown in Fig. The direction of force acting on the [1]
electron will be

a) into the page. b) to the right.

c) out of the page. d) to the left.

16. The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should [1]
be the position of the object?

a) Between the principal focus and the centre b) Beyond the centre of curvature
of curvature

c) At the centre of curvature d) Between the pole of the mirror and its
principal focus.
17. No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be: [1]

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 a) Either plane or convex b) Convex

c) Plane d) Concave
18. F e2 O3 + 2Al → Al2 O3 + 2F e [1]
The above reaction is an example of a

a) displacement reaction b) double displacement reaction

c) combination reaction d) decomposition reaction

19. Butanone is a four-carbon compound with the functional group [1]

a) aldehyde b) carboxylic acid

c) ketone d) alcohol
20. Which of the following is not a part of the female reproductive system in human beings? [1]

a) Fallopian Tubes b) Vas deferens

c) Uterus d) Ovary
Section B
21. What type of oxides are formed when non-metals combine with oxygen? [2]
22. Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans? [2]
23. How do Mendel's experiments show that traits may be dominant or recessive? [2]
24. An object, 4.0 cm in size, is placed at 25.0 cm in front of a concave mirror of focal length 15.0 cm. At what [2]
distance from the mirror should a screen be placed in order to obtain a sharp image? Find the nature and the size
of the image.
25. Calculate the number of electrons constituting one coulomb of charge. [2]
26. Why does a compass needle get deflected when brought near a bar magnet? [2]
Section C
27. A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold [3]
ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The
bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile
argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had
used?
28. A 2.0 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 10 cm. The [3]
distance of the object from the lens is 15 cm. Find the nature, position, and size of the image. Also, find its
magnification.
29. A current through a horizontal power line flows in east to west direction. What is the direction of magnetic field [3]
at a point directly below it and at a point directly above it?
30. A milkman adds a very small amount of baking soda to fresh milk. [3]
a. Why does he shift the pH of the fresh milk from 6 to slightly alkaline?
b. Why does this milk take a long time to set as curd ?
31. Describe double circulation of blood in human beings. Why is it necessary? [3]
32. What are the differences between aerobic and anaerobic respiration? Name some organisms that use the [3]
anaerobic mode of respiration.
33. A study found that children with light-coloured eyes are likely to have parents with light coloured eyes. On this [3]
basis, can we say anything about whether the light eye colour trait is dominant or recessive? Why or why not?

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 Section D
34. A 2.0 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 10 cm. The [5]
distance of the object from the lens is 15 cm. Find the nature, position, and size of the image. Also, find its
magnification.
35. Make a diagram to show how hypermetropia is corrected. The near point of a hypermetropic eye is 1 m. What is [5]
the power of the lens required to correct this defect? Assume that the near point of the normal eye is 25 cm.
36. Redraw the circuit putting in an ammeter to measure the current through the resistors and a voltmeter to measure [5]
the potential difference across the 12 Ω resistor. What would be the readings in the ammeter and the voltmeter?
Section E
37. Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results [4]
obtained have been tabulated as follows:

Iron(II) Copper(II) Zinc Silver

Metal
sulphate sulphate sulphate nitrate

A No reaction Displacement — —

B Displacement — No reaction —

C No reaction No reaction No reaction Displacement

D No reaction No reaction No reaction No reaction

Use the table above to answer the following questions about metals A, B, C and D.
i. Which is the most reactive metal?
ii. What would you observe if B is added to a solution of copper(II) sulphate?
iii. Arrange the metals A, B, C and D in the order of decreasing reactivity.
38. Draw the structures for the following compounds. [4]
i. Ethanoic acid
ii. Bromopentane*
iii. Butanone
iv. Hexanal.
*Are structural isomers possible for bromopentane?
39. Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube [4]
over it, as shown in figure below.
a. What will be the action of gas on
i. dry litmus paper?
ii. moist litmus paper?
b. Write a balanced chemical equation for the reaction taking place.

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