cbse class x mcqs practical based

W W W . C B S E 1 2 3 . C O . C C

S h i v r a j _ i t e r @ y a h o o . c o m

WWW.CBSE123.CO.CC The purpose of this eBook is make you give ample of practice in Practical based MCQs. This book is free of cost and can be distributed freely with due reference.

ABOUT WWW.CBSE123.CO.CC

It provides you with CBSE questions and answers, chapter wise notes, sample papers, MCQs, exam tips. All the materials have been written by KV teachers.

SCIENCE PRACTICAL SKILLS FROM WWW.CBSE123.CO.CC


SAMPLE QUESTION PAPER I

Time: 1 ½ hours Maximum Marks: 20

INSTRUCTIONS

1. Attempt all questions. 2. There are 30 multiple choice questions in total. Only one of the options in

every question is correct. 3. The question paper consists of two parts – Section A and Section B. Each of

the 20 questions in Section A carries 0.5 mark and each of the 10 questions in Section B carries 1.0 mark.

SECTION - A

1. The two colours seen at the extreme ends of the pH chart are

(a) red and blue. (b) red and green. (c) green and blue. (d) orange and green.

2. A student observed that the colour of pH paper changes to green when she dipped it in water. She added a few drops of concentrated hydrochloric acid to the water. The colour of pH paper would turn to

(a) light red. (b) apple green. (c) dark blue. (d) lemon yellow.

3. When zinc reacts with dilute hydrochloric acid

(a) the surface of zinc becomes brighter. (b) the surface of zinc becomes black and dull. (c) the metal turns into powder. (d) the reaction mixture turns green.

4. Three students measured the focal length of a convex lens using parallel rays from a distant object. All of them measured the distance between the lens and the inverted


image on the screen. Student A saw a sharp image on the screen and labelled the distance as f1. Student B saw a slightly larger blurred image on the screen and labelled the distance as f2. Student C saw a slightly smaller blurred image on the screen and labelled the distance as f3. The relation between the three measurements would most likely be

(a) f1 = f2 = f3. (b) f1 < f2 and f3. (c) f3 < f1 < f2. (d) f1 < f2 and f1= f3.

5. Four students A, B, C and D carried out measurements of focal length of a concave mirror as shown in the four diagrams.


The best result will be obtained by student

(a) A. (b) B. (c) C. (d) D.

6. In the glass slab experiment shown below, four students A, B, C and D did the following:

A: kept the eyes far from the glass slab while placing both the pins P3 and P4

B: kept the eyes close to the glass slab while placing both the pins P3 and P4

C: kept the eyes close to the glass slab while placing pin P3 and far from theslab while placing pin P4

D: kept the eyes far from the glass slab while placing pin P3 and close to the slab while placing pin P4

The correct procedure is that of student

(a) A. (b) B. (c) C. (d) D.


7. Out of the four circuits shown for studying the dependence of the current on the potential difference across a resistor, the correct circuit is

(a) A. (b) B. (c) C. (d) D.

8. The plot correctly showing the dependence of the current I on the potential difference V across a resistor R is

(a) A. (b) B. (c) C. (d) D.


9. For the circuits shown in figures I and II, the ammeter readings would be

(a) 1 A in circuit I and 0A in circuit II. (b) 0 A in both circuits. (c) 1 A in both circuits. (d) 0 A in circuit I and 1 A in circuit II.

10. The voltmeter, ammeter and resistance in the circuit shown have been checked to be correct. On plugging the key, the ammeter reads 0.9 A, but the voltmeter reads zero. This could be because

(a) the range of the voltmeter is more than the twice the battery voltage. (b) the least count of the voltmeter is too high. (c) the wires joined to the voltmeter terminals are loose. (d) the voltmeter is incorrectly placed in the circuit


11. What colour appears if HCl is added to adulterated arhar dal with metanil yellow?

(a) Yellow (b) pink (c) blue (d) red

12. In an experiment on photosynthesis, students were instructed to cover a portion of a leaf of a de-starched potted plant with opaque paper as shown in the figure.

“A” covered one of the leaves with red strip, “B” with green, “C” with blue and “D” with black. When the starch test was done on the leaves after 4 hours, the result showed no starch in

(a) The portion covered with red, green and blue strips. (b) The portion covered with green strip. (c) The portion covered with black and blue strips. (d) any of the covered portions


13. Given below are four different set ups to show that CO2 is released during respiration.

The set up that will give the desired result is

(a) A. (b) B. (c) C. (d) D.


14. Students A, B and C were given five raisins each of equal weight. The raisins were soaked in distilled water at room temperature. A removed the raisins after 20 minutes, B after two hours and C after 40 minutes. If PA, PB and PC denote percentage absorption of water obtained by students A, B and C respectively, then

(a) PA > PB > PC. (b) PA < PB < PC. (c) PA < PB > PC. (d) PA = PB = PC.

15. The budding in yeast is illustrated by the diagram

(a) A. (b) B. (c) C. (d) D.

16. A student dissolved 1 g of sugar in 10 mL of distilled water in a beaker A. He dissolved 10 g of sugar in 100 mL of distilled water in beaker B. Then he dropped a few raisins, in each. After two hours he found the raisins

(a) swollen in A and shrunken in B. (b) shrunken in A and swollen in B. (c) swollen in both. (d) shrunken in both.

17. 10 mL of freshly prepared iron sulphate was taken in each of four test tubes. Strips of copper, iron, zinc and aluminium were introduced, each metal in a different test tube. A black residue was obtained in two of them. The right pair of metals forming the precipitates is

(a) copper and zinc. (b) aluminium and copper.


(c) iron and aluminium. (d) zinc and aluminium.

18. The following symbols are usually shown on the bottles of commercial acetic acid.

The symbols indicate that acetic acid is

(a) corrosive and flammable. (b) radioactive and flammable. (c) oxidizing and corrosive. (d) flammable and explosive.

19. A strip of copper was placed in a beaker containing zinc sulphate solution. On observing the strip the next day, it was noticed that

(a) the copper strip remained as it was. (b) the copper strip became thinner. (c) the copper strip became thicker. (d) the colour of the strip changed.

20. Amount of 5 mL each of acetic acid and water are mixed together and shaken well.


The resulting mixture would appear as in

(a) I. (b) II. (c) III. (d) IV.

SECTION B

21. When a strong beam of light falls on a suspension of chalk powder and water, the light

(a) Hardly passes through the suspension (b) Passes through the suspension (c) Gets scattered in the suspension (d) None of the above

22. Out of the four set ups shown for carrying out the experiment to trace the path of a ray of light through a rectangular glass slab, the best set up is


(a) A. (b) B. (c) C. (d) D.

23. The correct experimental setup for studying the variation of time period with length of simple pendulum is shown in figure:

(a) A. (b) B. (c) C. (d) D.

24. The temperature time variation graphs as obtained by four students A, B, C and D are shown. The graph likely to be correct is of student:

(a) A. (b) B. (c) C. (d) D.


25. A student performed the starch test on a leaf. Some steps involved are shown below.

The correct sequence of steps should be

(a) iv; iii; ii; i. (b) i; ii; iii; iv. (c) ii; iii; iv; i. (d) i; iii; iv; ii .

26. A part of de-starched leaf of a potted plant was covered with black paper strips on both sides and the plant was kept in sunlight for 8 hours. The leaf was then tested with


iodine after boiling it in alcohol. Only the uncovered part of the leaf turned blue black. The inference is that

(a) CO2 is necessary for photosynthesis. (b) light is necessary for photosynthesis. (c) chlorophyll is necessary for photosynthesis. (d) water is necessary for photosynthesis.

27. In the experiment shown in the figure, water is found to rise in the bent tube.

The reason is that

(a) seeds use up oxygen in the flask. (b) carbon dioxide is given out by the germinating seeds. (c) germinating seeds attract water from the beaker. (d) seeds use oxygen and release carbon dioxide which is absorbed by (a) potassium hydroxide.

28. Glycerine is used to prepare a temporary mount of a tissue due to the following reason

(a) to colour the specimen (b) to avoid drying up of the specimen quickly (c) to avoid entry of air bubbles (d) none of the above

29. For preparing sulphur dioxide in the laboratory the correct set up is shown in figure


(a) I. (b) II. (c) III. (d) IV.

30. A student added acetic acid to test tubes I, II, III and IV and then introduced a burning candle near the mouth of each test tube


The candle would not be extinguished near the mouths of test tubes

(a) I and II. (b) II and III. (c) III and IV. (d) I and IV.


SAMPLE QUESTION PAPER I


INSTRUCTIONS





SAMPLE QUESTION PAPER III


INSTRUCTIONS





5. A block of wood of mass 100g is placed on a smooth table in the experiment set up used in the study of limiting friction. A student is asked to choose from the following:

i. Either pan of mass 30g or 10g ii. Either slotted discs of mass 10g each 2g each

The most suitable combination that she should choose would be


(a) Pan of 30g and slotted discs of 10g each (b) Pan of 30g and slotted discs of 2g each (c) Pan of 10g and slotted discs of 10g each (d) Pan of 10g and slotted discs of 2g each


8: Four students reported the following observation tables for the experiment, to trace the path of a ray of light passing through a glass slab for different angles of incidence. The observations, likely to be correct are those of student.

(a) I (b) II (c) III (d) IV

9. Your school laboratory has one large window. To find the focal length of a concave mirror using one of the walls as the screen, the experiment may be performed.

(a) near the wall opposite to the window. (b) on the same wall as the window. (c) on the wall adjacent to the window. (d) only on the table as per the laboratory arrangement.

10. In order to prepare a temporary mount of a leaf peel of observing stomata, the chemicals used for staining and mounting respectively are

(a) Saffranin and glycerine (b) lodine and glycerine (c) lodine and saffranin (d) glycerine and saffranin


ZnSO4

splinter.


22: Four different measuring instruments are shown below. Out of these, the instrument that can be used for measuring current is/are the instruments labeled as

(a) I and III with I more reliable of the two (b) I and IV with IV more reliable of the two (c) II and III with II more reliable of the two (d) II and IV with IV more reliable of the two


24. A dilute solution of sodium carbonate was added to two test tubes – one containing dil HCl (A) and the other containing dilute NaOH (B). The correct observation was

(a) A brown coloured gas librated in test tube A. (b) A brown coloured gas librated in test tube B. (c) A colourless gas librated in test tube A. (d) A colourless gas librated in test tube B.

25. A copper sulphate solution is added to a test tube containing a cleaned iron nail. The correct description regarding the deposition of copper on the iron nail would be that it starts depositing.

(a) at the tip of the nail. (b) from the head of the nail. (c) in the middle of the nail. (d) anywhere on the nail.

26. A student is asked to add a tea spoon full of solid sodium bicarbonate to a test tube containing approximately 3 mL of acetic acid. He observed that the solid sodium bicarbonate

(a) floats on the surface of acetic acid. (b) remains suspended in the acetic acid. (c) Settles down in the test tube. (d) reacts with acetic acid and a clear solution is obtained.


SAMPLE QUESTION PAPER IV


INSTRUCTIONS




SECTION - A

1. Which one of the following is not required to find the pH of a solution ?

(a) pH paper (b) Litmus paper (c) Universal indicator (d) Standard pH value chart

2. A drop of a liquid sample was put on the pH paper. The colour of the pH paper turned blue. The liquid sample could be that of

(a) Lemon juice (b) Hydrochloric acid (c) Sodium bicarbonate solution (d) Ethanoic acid

3. Dilute hydrochloric acid is added to solid sodium carbonate. It is observed that

(a) no change takes place (b) a loud sound is produced (c) brisk effervescence occurs (d) the solution turns

4. Which one of the following combinations of substances would you take to prepare sulphur dioxide gas ?


(a) Concentrated Sulphuric acid and Zinc (b) Dilute Sulphuric acid and Zinc (c) Dilute Sulphuric acid and Copper (d) Concentrated Sulphuric acid and Copper

5. A teacher gave two test tubes, one containing water and the other containing sodium hydroxide solution, to the students and asked them to identify the test tube containing sodium hydroxide solution. Which one of the following can be used for correctly identifying the test tube containing sodium hydroxide solution ?

(a) Blue litmus (b) Red litmus (c) Sodium carbonate solution (d) Dilute hydrochloric acid

6. The following substances are added to a beaker as shown below and is stirred will. A true solution is found in the beaker:


7. When we start heating a mixture of sulphur powder and iron fillings, we would observe that

(a) Sulphur starts melting (b) Iron filings start melting (c) Mixture becomes red hot


(d) Mixture evaporates.

8. A student obtained a sharp image of the grill of a window on a screen, using a convex lens. For getting better results, the teacher suggested focussing of a distant tree instead of the grill. In which direction should the lens be moved for this purpose ?

(a) Away from the screen (b) Very far away from the screen (c) Behind the screen (d) Towards the screen

9. The image of a distant object is obtained on a screen by using a concave mirror. The focal length of the mirror can be determined by measuring the distance between

(a) the object and the mirror (b) the object and the screen (c) the mirror and the screen (d) the mirror and the screen as well as that between the object and the screen

10. Which one of the following is the best set-up for tracing the path of a ray of light through a rectangular glass slab ?

(a) I (b) II (c) III


(d) IV

11. The following circuit diagram shows the experimental set-up for the study, of dependence of current on potential difference. Which two circuit components are connected in series ?

(a) Battery and voltmeter (b) Ammeter and voltmeter (c) Ammeter and rheostat (d) Resistor and voltmeter

12. In a voltmeter, there are 20 divisions between the 0 mark and 0-5 V mark. The leas count of the voltmeter is

(a) 0.020 V (b) 0.025 V (c) 0.050 V (d) 0.250 V

13. For the simple pendulum shown in the figure, the effective length is:

(a) AP (b) OP (c) CP (d) CQ


14. The correct arrangement for taking temperature in the study of the temperature-time graph is shown in figure:

(a) A (b) B (c) C (d) D

15. A portion of each of four destarched leaves of a plant was covered with paper strips of various kinds. The plant was exposed to sunlight for 5 hours. Thereafter, the strips


were removed and the leaves tested for starch in the covered portion. Which one out of the four leaves gave the starch test in the covered portion ?

(a) That covered with black paper strip (b) That covered with green paper strip (c) That covered with white paper strip (d) That covered with a transparent paper strip

16. A well stained leaf peel preparation when focussed under high power of the microscope would show

(a) epidermal cells, stomata, guard cells each with one nucleus and many chloroplasts

(b) epidermal cells, stomata, guard cells with many nuclei and one chloroplast each (c) stomata and guard cells without nuclei or chloroplasts (d) stomata but no guard cells or epidermal cells

17. The following experiment was set up to show that a gas is given out during respiration. But there was no rise in the level of water. This was because

(a) germinating seeds have not been kept under water in the flask (b) water is kept in the beaker instead of lime water (c) the cork on the flask is made of rubber (d) no substance is kept in the flask to absorb the gas given out by the seeds


18. Human cheek cell stained in methylene blue and mounted in glycerine were observed under a compound microscope. The components of cell which would be seen are

(a) cell wall, cytoplasm, nucleus (b) plasma membrane, cytoplasm, nucleus (c) plasma membrane, cytoplasm, nucleus, mitochondria (d) plasma membrane, nucleus, mitochondria lysosomes

19. X was rushing with a bottle of iodine solution. Some iodine solution splashed on his yellow coloured cotton shirt and also on the white table cloth. The stain on the table cloth was yellowish brown while that on his shirt was blue black. The most plausible scientific reason for this is that the

(a) shirt was dyed with metanil yellow (b) shirt was starched after washing (c) table cloth was starched but not shirt (d) shirt had absorbed sweat

20. A student soaked 5 grams of raisins in 25 mL of distilled water in each of two beakers A and B. Beaker A was maintained at 25 °C and beaker B at 50 °C. After one hour, the student observed that the water absorbed by the raisins was

(a) same in case of A and B (b) less in case of A than in B (c) exactly double in A, of that in B (d) exactly four times in A, of that in B

SECTION B

21. Given below are certain chemical properties of substances.

(a) It turns blue litmus red. (b) It turns red litmus blue. (c) It reacts with zinc and a gas evolves. (d) It reacts with solid sodium carbonate to give brisk effervescence.

Which out of these properties are shown by dilute hydrochloric acid ?

(a) (a) and (b) only


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

22. A student was asked to demonstrate the following two properties of sulphur dioxide gas : (i) It is heavier than air, and (ii) It is highly soluble in water. Which two of the following four arrangements would the student use to demonstrate these properties?

(a) I and II (b) II and III (c) I and III (d) II and IV

23. Iron filings were added to a solution of copper sulphate. After 10 minutes, it was observed that the blue colour of the solution changes and a layer gets deposited on iron filings. The colour of the solution and that of the coating would, respectively, be :

(a) yellow and green (b) brown and blue (c) red and greenish-blue (d) green and reddish-brown

24. The current flowing through a conductor and the potential difference across its two ends are as per readings of the ammeter and the voltmeter shown below. The resistance of the conductor would be

(a) 0.02 Ω (b) 0.024 Ω (c) 20.0 Ω (d) 24.0 Ω


25. The following instruments are available in a laboratory :

Milliammeter A1 of range 0 - 300 mA and least count 10 mA

Milliammeter A2 of range 0 - 200 mA and least count 20 mA

Voltmeter V1 of range 0 - 5 V and least count 0.2 V

Voltmeter V2 of range 0 - 3 V and least count 0.3 V

Out of the following pairs of instruments, which pair would be the best choice for carrying out the experiment to determine the equivalent resistance of two resistors connected in series ?

(a) Milliammeter A1 and voltmeter V1 (b) Milliammeter A2 and voltmeter V2 (c) Milliammeter A1 and voltmeter V2 (d) Milliammeter A2 and voltmeter V1

26. In an experiment to determine equivalent resistance of two resistors R1 and R2 in series, which one of the following circuit diagrams shows the correct way of connecting the voltmeter in the circuit ?



27. Which one of the following is the combination of relevant materials required for setting up an experiment to show that light is necessary for photosynthesis ?

(a) Destarched leaves, strips of black paper, starch solution and iodine crystals (b) A potted plant, strips of coloured paper, starch solution, iodine and potassium

iodide (c) Destarched leaves, strips of black paper, starch solution and potassium iodide (d) Destarched leaves, strips of black paper and iodine solution

28. While performing an experiment to determine the percentage of water absorbed by raisins, the following data was obtained : Mass of water taken in the beaker = 50 g. Mass of raisins before soaking them in water = 5 g. Mass of raisins after soaking in water for 2 hours = 8 g. The percentage of water absorbed by raisins would be

(a) [(8-5)g/8g]x100 (b) [(8-3)g/8g]x100 (c) [(8-5)g/3g]x100 (d) [(8-5)g/5g]x100


30. A student was asked to focus a permanent slide under the high power of a microscope. This involved the following steps which have not been written in a correct sequence :

A. Place the slide on the stage. B. Clean the microscope and lenses. C. Focus the material with the help of coarse adjustment. D. Place the low power objective lens above the slide. E. Sharpen the focus with fine adjustment. F. Bring high power objective lens over the slide.

Which one of the following is the correct sequence of steps for focusing the slide under high power ?

(a) A, B, C, D, E, F (b) B, A, C, D, E, F (c) A, B, F, C, D, E (d) B, A, D, C, F, E

30. Which one out of the following sets of diagrams correctly depicts reproduction in amoeba and yeast?


SAMPLE QUESTION PAPER V


INSTRUCTIONS




SECTION - A

1. A sharp image of a distant object is obtained on a screen by using a convex lens. In order to determine the focal length of the lens, you need to measure the distance between the

(a) lens and the object. (b) lens and the screen. (c) object and the screen. (d) lens and the screen and also object and the screen.

2. A student obtains a blurred image of an object on a screen by using a concave mirror. In order to obtain a sharp image on the screen, he will have to shift the mirror

(a) towards the screen. (b) away from the screen; (c) either towards or away from the screen depending upon the position of the

object. (d) to a position very far away from the screen.

3. Three students used different kinds of attachments while measuring limiting friction of a block placed over a table. Students A used a rubber band; B used a woolen thread; C used a cotton thread. The best choice is:

(a) that of A (b) that of B (c) that of C


(d) independent of the kind of attachment used

4. The path of a ray of light passing through a rectangular glass slab was traced and angles measured. Which one out of the following is the correct representation of an angle of incidence i, angle of refraction r and angle of emergence e as shown in the diagrams ?


5. Which two circuit components are connected in parallel in the following circuit diagram ?

(a) Rheostat and voltmeter (b) Voltmeter and ammeter (c) Voltmeter and resistor (d) Ammeter and resistor

6. An ammeter has 20 divisions between mark 0 and mark 2 on its scale. The least count of the ammeter is

(a) 0.02 A


(b) 0.01 A (c) 0.2 A (d) 0.1 A

7. In the experiment to establish the relation between loss in weight of an immersed solid with the weight of water displaced by it, the correct setup is shown in figure

(a) A (b) B (c) C (d) D

8. A little dilute hydrochloric acid is dropped on a pH paper. The colour of the pH paper turns to

(a) dark pink (b) light green (c) light blue (d) bright yellow

9. The correct method of finding the pH of a solution is to

(a) heat the solution in a test tube and expose the pH paper to the vapours formed. (b) pour few drops of the solution from the test tube on the pH paper. (c) drop the pH paper in the solution. (d) put a drop of the solution on the pH paper using a dropper.


10. Which one of the following will be required to identify the gas evolved when diluted hydrochloric acid reacts with zinc metal ?

(a) Blue litmus solution (b) Red litmus solution (c) A burning splinter (d) Lime water

11. A liquid sample turned red litmus paper blue. This indicates that the liquid sample is that of

(a) an alcohol (b) distilled water (c) sodium hydroxide solution (d) hydrochloric acid

12. Sulphur dioxide gas is collected in the laboratory by the

(a) upward displacement of air. (b) downward displacement of air. (c) upward displacement of water. (d) downward displacement of water.

13. Some crystals of copper sulphate were dissolved in water. The colour of the solution obtained would be

(a) green (b) red (c) blue (d) brown

14. When the stopper of a bottle containing a colourless liquid was removed, the bottle gave out a smell like that of vinegar. The liquid in the bottle could be

(a) hydrochloric acid solution. (b) sodium hydroxide solution. (c) acetic acid. (d) saturated sodium bicarbonate solution.


15. A student put five raisins each in two beakers A and B. Beaker A contained 50 mL of distilled water an’d beaker B had 50 mL of saturated sugar solution. After some time the student would observe that

(a) raisins in beaker A were more swollen than those in beaker B. (b) raisins in beaker B were more swollen than those in beaker A. (c) raisins in both beakers A and B were equally swollen. (d) raisins in beaker A did not swell up at all.

16. Before carrying out the test for the presence of starch in a leaf on exposure to sunlight, the leaf is put into alcohol contained in a beaker and boiled over a water bath. This step is carried out to

(a) extract starch (b) dissolve chlorophyll (c) allow water to move into the leaf (d) make membranes of leaf cells more permeable

17. When ice converts into water

(a) temperature is increased (b) heat is absorbed (c) heat is released (d) temperature is increased

18. When a strong beam of light falls on a suspension of chalk powder and water, the light

(a) Hardly passes through the suspension (b) Passes through the suspension (c) Gets scattered in the suspension (d) None of the above

19. The part that prevents loss of water and the part that stores water, in the plant shown in this drawing are:

(a) A and D (b) B and A (c) C and B


(d) D and C

20. Diagrams of the cells of onion peel were labelled by four students as given below. The correctly labelled diagram is:

(a) A (b) B (c) C (d) D

SECTION B

21. Solutions of ferrous sulphate, zinc sulphate, copper sulphate and aluminium sulphate were separately taken in four test tubes and some iron nails were placed in each of the solutions. After few minutes, it would be observed that the colour of

(a) all the four solutions changed. (b) solutions of zinc sulphate, copper sulphate and aluminium sulphate changed and

that of ferrous sulphate did not change. (c) solutions of zinc sulphate and aluminium sulphate only changed.


(d) copper sulphate solution only changed.

22. When sodium bicarbonate powder is added to acetic acid, a gas evolves. Which one of the following statements is not true for this gas ? It

(a) turns lime water milky. (b) extinguishes a burning splinter. (c) dissolves in a solution of sodium hydroxide. (d) turns acidified potassium dichromate solution green.

23. When acidified potassium dichromate solution is added to a jar containing sulphur dioxide gas, the solution becomes

(a) colourless (b) brown (c) dark orange (d) green

24. The correct set up for determining the equivalent resistance of two resistors R1 and R2 when connected, in parallel is



25. To determine the equivalent resistance of a series combination of two resistors a student arranges the following set up : Which one of the following statements will be true for this circuit ? It gives :

(a) incorrect reading for current 1 as well as potential difference V. (b) correct reading for current I but incorrect reading for potential difference V. (c) correct reading for potential difference V but incorrect reading for current I. (d) correct readings for both I and V

26. The current flowing through a resistor connected in an electrical circuit and the potential difference developed across its ends are shown in the given diagrams : The value of resistance of the resistor in ohms is

(a) 25 (b) 20 (c) 15 (d) 10


27. For determining the percentage of water absorbed by raisins in a given time, apart from water, raisins and a watch, we shall also require

(a) a beaker, a graduated cylinder, a thermometer, a filter paper. (b) a watch glass, a graduated cylinder, a thermometer, a weighing balance. (c) a beaker, a thermometer, a filter paper, a weighing balance. (d) a graduated cylinder, a thermometer, a weighing balance.

28. Four students focussed an epidermal peel of leaf under high power and made the following sketches. Which one out of the following is correctly sketched ?


29. A black strip of paper was clipped on to a destarched leaf in a potted plant to cover a part of the leaf. The plant was then exposed to sunlight for four hours, the paper strip was removed and the leaf tested for starch. When Iodine solution was added

(a) the entire leaf turned blue-black. (b) the covered part of the leaf became blue-black. (c) the uncovered part of the leaf became blue-black.


(d) the colour of Iodine solution remained unchanged.

30. Out of the four experimental set-ups shown below, which one will demonstrate the evolution of carbon dioxide during respiration of germinating seeds ?



ANSWERS OF SAMPLE PAPERS

QUES. SP1 SP2 SP3 SP4 SP5 1 A B B/C B B 2 A C B C C 3 B C A C C 4 C A B B D 5 A B D B C 6 A C B B D 7 B D A C B 8 A A B A D 9 D A A C C

10 C C A D C 11 B D C C C 12 D D B D A 13 C B D B C 14 C B C A C 15 B A A D A 16 C A C A B 17 D B D D B 18 D B C B A 19 A C C B C 20 C D D B C 21 A A B C D 22 B C A D C 23 C D A D C 24 B B C C B 25 D D D A B 26 B C D C D 27 D B C D C 28 B D D D B 29 A A D D C 30 C C B B D

cbse class x mcqs practical based

Documents