Series LRH/1
PRACTICAL SKILLS IN SCIENCE
Time allowed : I/2 hours TEST BOOKLET Maximum marks : 20
Section A
1.The white of an egg, common salt, sugar and fine sand are added to water separately in beakers as shown below. The mixture is stirred well. A suspension will be formed in the beaker :
2.The correct procedure of heating iron-sulphur mixture to prepare iron sulphide is :
(1) heat the powder mixture at the base of the test tube using a blue flame throughout.
(2) heat the iron filing sulphur mixture in the middle of the test tube using yellow flame throughout.
(3) heat the powder mixture at the top of the test tube using an orange flame throughout.
(4) heat the iron filing-sulphur mixture at 3/4 quarters of the test tube using a red flame throughout.
3.A student while heating solid lead nitrate taken in a test tube would observe :
(1) white residue of PbO2
(2) green residue of NO2
(3) yellow residue of PbO
(4) brown residue of NO
4.The following precautions were listed for the experiment on determination of melting point of ice. The incorrect precaution is :
(1) The bulb of the thermometer should be kept surrounded with crushed ice.
(2) Ice should be stirred regularly to keep a uniform temperature throughout.
(3) The final temperature should be noted by keeping the eyes in line with the level of mercury.
(4) Only the tip of the bulb of the thermometer should just touch the crushed ice.
5.For verifying the laws of reflection of sound, a student has to choose from
(i) a black polished metal sheet or a white thermocole sheet
(ii) a 0.5 m long tube of diameter 3 cm or a 1.5 m long tube of diameter 20 cm
He should prefer to choose the :
(1) metal sheet and the 0.5 m long tube
(2) metal sheet and the 1.5 m long tube
(3) thermocole sheet and the 0.5 m long tube
(4) thcrmocole sheet and the 1.5 m long tube
6.The zero-error, in the spring balance shown and the correct weight of the solid, suspended from it, are equal, respectively, to : 
(1) +2gwt; 19gwt
(2) +2gwt; 15gwt
(3) -2gwt; 19gwt
(4) - 2gwt; 15gwt
7.Two students X and Y have to do their experiment on plotting the temperature-time graph for a hot body as it cools to room temperature. They do their experiments in the same lab, using completely identical apparatus, take equal amounts of tap water heated up to the same temperature, start their observations simultaneously and note the temperature values at identically spaced intervals of time. Their temperature-time graphs, plotted on a given graph paper, with the same given choices of scales along the axis, are, however, as shown.
The following could he the reason for this difference
A. Use of an overhead fan by student X.
B. Use of an overhead fan by student Y.
C. Less frequent stirring of water by student X.
D. Less frequent stirring of water by student Y.
The most likely reason is
(1) A
(2) B
(3) C
(4) D
8.A student lists the following precautions for the experiment on determining the velocity of a pulse propagated through a stretched string.
(A) The string should not be stretched too tight.
(B) The counting of the pulse journeys must start from zero and not from one.
(C) The string should be stretched straight in contact with the table.
(D) The amplitude of the pulse should be kept appreciably high.
The incorrect entry, in this list of precautions, is the precaution listed
9.In the diagram of cockroach given below, the part characteristic of its phylum is the part labelled as :
(1) A
(2) B
(3) C
(4) D
10.The four pictures of the microscope given below show the manner in which a microscope should be handled. The picture that shows the correct way of using the coarse adjustment while viewing through the high power objective is :
(1) A
(2) B
(3) C
(4) D
11.To a sample of turmeric adulterated with metanil yellow, concentrated hydrochloric acid was added. The colour of the reaction mixture :
(1) disappeared
(2) remained the same
(3) became pink
(4) became black
12.A student adds a few drops of the universal indicator to a dilute solution of sodium bicarbonate taken in a test tube.
Which of the following colours, would he observe :
(1) blue
(2) green
(3) mustard
(4) yellow
13.A student placed a few drops of a liquid over a portion of the blue litmus paper as shown here. He observed that the blue litmus paper turned red. The liquid could be :
(1) dilute hydrochloric acid
(2) dilute sodium hydroxide
(3) dilute sodium bicarbonate solution
(4) water
14.A student strongly heats hydrated ferrous sulphate salt in a dry test tube. He would observe a :
(1) yellow residue
(2) brown residue
(3) light green residue
(4) white residue
15.A student was given the following `suggestions' by his fellow students for performing the experiment on finding the focal length of a convex lens.
(A) Select an object very far away from the laboratory window.
(B) Select a well illuminated object far, but not very far, from the laboratory window.
(C) Keep all lights of the lab on.
(D) Place the lens between the object and screen.
(E) Place the screen between the object and the lens.
(F) Obtain the sharpest image of the object on the screen.
He can perform the experiment better by following the suggestions
(1) A, D, F
(2) B, C, E
(3) C, F, B
(4) D,F,B
16.In the experiment on tracing the path of a rays of light passing through a rectangular glass slab, the correct setting of the protractor (D), for measuring the angle of incidence (<i), and the angle of emergence (<e), correspond, respectively, to diagrams is :
(1) KandM
(2) K and N
(3) Land M
(4) L and N
17.A student sets up the circuit, for studying the dependence of current (I) flowing, on the applied potential difference (V), in the manner shown. The ammeter and the voltmeter, in his circuit, have been checked and found to be correct. On closing the key K, he observes a deflection in the ammeter but no deflection in the voltmeter. This could be due to a loose connection, or break, in the wire :
(1) W1 or W2
(2) W3 or W4
(3) W5 or W6
(4) W6 or W1
18.Glycerine is used while making slides of onion peel. It is needed to :
(1) clean the slide
(2) retain the stain
(3) mount the material on the slide
(4) fix the coverslip on the slide forever
19.A student had drawn the diagram of stomata as shown below in a hurry. He could not be given full marks as he:
(1) forgot to draw nuclei in guard cells and also to label the diagram
(2) did not draw nuclei, in guard cells and other cells
(3) should have drawn nuclei and chloroplasts in guard cells and nuclei in all epidermal cells
(4) did not label the stoma in its correct position
20.This is a figure of the female cone. It is found in the : 
(1) capsule of moss
(2) annulus of the mushroom
(3) fruit of the pineapple
(4) branches of pinus
21. Which of the following is the correct set up of apparatus to separate common salt and sand by filtration process :
22.In the set up shown the weight of the body was measured in air and in water.
The reading of mark X in the spring balance would be :
(1) 36 g wt
(2) 30 g wt
(3) 24 g wt
(4) 6 g wt
23.
The correct labelling of the figure is :
(1) P :Rachis ; Q : Pinnules ; R : Rhizome ; S : Adventitious roots
(2) P : Branch ; Q : Leaflets ; R : Thallus ; S : Roots
(3) P : Rachis ; Q : Leaves : R : Stem ; S : Tap root
(4) P : Mid rib ; Q : Compound leaves; R : Stem ; S : Root hairs
In the experimental set up shown above, KOH solution has been kept in the flask to :
(1) react with water to generate oxygen.
(2) create a dry atmosphere for wet germinating seeds.
(3) absorb carbon dioxide so as to create a partial vacuum.
(4) remove impurities present in the air in the flask.
25.A student took four test tubes containing solution of different colours marked I, II, III and IV as shown below. The test tubes, containing copper sulphate solution and ferrous sulphate solution, could be the tubes :
(1) I and III
(2) II and III
(3) III and IV
(4) II and IV
26.Four students added a small amount of ethanoic acid to sodium bicarbonate. The gas evolved was tested for its behaviour with burning splinter and lime water.
| Student | Gas evolved | Action of burning splinter | Action of lime water |
| A | CO2 | The flame of splinter extinguishes and gas does not burn | Turned milky |
| B | SO2 | The splinter bums brightly and the gas burns with a pop | Turned green |
| C | NO2 | The gas does not bum but the splinter burns with a hissing sound | Turned black |
| D | O2 | The gas bums with a yellow flame and the splinter extinguishes | Turned purple |
The correct observations have been reported by student :
(1) A
(2) B
(3) C
(4) D
27.The values of resistances marked on the coils R, and R2 are found to be correct. A student connects the given resistors in the following manner.
He then connects the terminals X Y marked X and Y above
to the terminals marked X and Y in the circuit.
The average value of the ratio V/I in the observations
recorded in the circuit would be :
(1) 9 52 (2) 652
(3) 352 (4) 2 Q
28.Three students X, Y and Z, while performing on the experiment to study the dependence of current on the potential difference across a resistor, connects the ammeter (A), the battery (B), the key (K) and the resistor (R), in series, in the following three different orders.
X -->B,K,R,A,B
Y-->B,A,K,R,B
Z-->B,R,K,A,B
Who has connected them in the correct order ?
(1) X (2) Y (3) Z (4) All of them
29.A star-shaped figure was cut in the black paper strip used for covering the leaf of a destarched plant used for demonstrating that light is necessary for photosynthesis. At the end of the experiment when the leaf was tested for starch with iodine, the star-shaped figure on the leaf was found to be :
(1) colourless
(2) green in colour
(3) brown in colour
(4) blue-black in colour
30.
The figures above are drawn from slides showing reproduction in yeast and amoeba. The correct description of the above is :
(1) Amoeba undergoing binary fission is at a stage when nucleus is elongating, while yeast has undergone budding.
(2) Yeast is undergoing binary fission and daughter nuclei have already formed, while a newly formed daughter amoeba is undergoing growth.
(3) The nucleus of a parent amoeba is undergoing division to pass into its bud while yeast has already divided into two daughter cells.
(4) Amoeba is undergoing cytokinesis and yeast is undergoing budding.