Reference no: EM131561200

SECTION A

1 Name the instrument used to measure electric current in a circuit.

2 In which part of the digestive system is water absorbed?

3 Write the full form of CNG.

4 State the type of chemical reaction with chemical equation that take place in the following:
a) Magnesium ribbon is burnt in air
b) Electric current is passed through water

5 Explain the action of dilute hydrochloric acid on the following with chemical equation:
a) Sodium metal
b) Calcium carbonate

6 a) How brain and spinal cord are protected in humans?
b) Name the master gland present in the brain. Which hormone is released by it?

7 2g of ferrous sulphate crystals are heated in a boiling tube:
a) List any two observations.
b) Name the type of reaction taking place.
c) Write the chemical equation involved

8 Which three chemical substances are obtained when electricity is passed through aqueous solution of Brine. Write one industrial use of each.

9 Differentiate between the following with suitable examples:
a) Mineral and ore
b) Malleability and ductility.
c) Corrosion and rancidity.

10 What are magnetic field lines? Justify the following statements:
a) No two magnetic field line can intersect each other.
b) Magnetic field lines are closed curves.

11 What change in the galvanometer would you observe when a strong bar magnet is:
a) Kept stationary at a distance from the coil?
b) Pushed towards the coil.
c) Pushed away from the coil. Give reasons to justify your answer.

12 Name two hormones secreted by pancreas. Write one function of each.

13 Draw a neat diagram of human excretory system and label any six parts.

14 Find the equivalent resistance across the two ends A and B of the following circuits.

15 Explain the process of breakdown of glucose in a cell:
a) In the presence of oxygen
b) In the absence of oxygen

16 a) Classify the given solutions into acidic or basic giving reasons:
Solution A: [H⁺] < [OH^-]
Solution B: [H⁺] > [OH^-]
b) Give one characteristic test for CO₂ gas.

17 List any three characteristics of a good fuel.

18 Sehaj suggests his family to install a solar water heater at their residence. But some of the family members were in a favor of installing an electric geyser.
a) Who according to you is taking a correct decision?
b) Mention the values exhibited by Sehaj.
c) Also give reasons for your answer.

19 a) Write any two properties of ionic compounds?
b) Show the formation of aluminium chloride by the process of transfer of electrons.( atomic number of aluminium and chlorine is 13 and 17 respectively).
c) What is thermite reaction? How is it used to join the railway tracks or cracked machine parts?

20 Draw a labelled diagram of human brain. Write the functions of Medulla, cerebellum and forebrain.

21 A white colored powder is used by doctors to support fractured bones.
a) Write chemical name and formula of the powder.
b) Give its preparation.
c) Why it should be stored in moisture proof containers?

22 a) What is overloading? State the causes of overloading.
b) Explain, why fuse wire is made of a tin lead alloy and not copper?

23 a) State ohm's law. Explain mathematically.
b) Write symbols used in electric circuits to represent: rheostat and voltmeter
c) An electric bulb is rated 220V and 100 W. When it is operated on 110 V, what will be the power consumed?

24 Describe an activity to demonstrate the pattern of magnetic field lines around a straight conductor carrying current. Name and state the rule to find the direction of magnetic field associated with a current carrying conductor.

SECTION B

25 A colorless sample was tested with a strip of pH paper. The color of the strip changed to green. The sample should be:
a) Tap water
b) Distilled water
c) Sodium hydroxide
d) Lemon juice

26 Dilute HCl is poured over solid Na₂CO₃ taken in test tube. The gas evolved is:
a) CO
b) CH₄
c) CO₂

d) N₂

27 On heating crystals of ferrous sulphate, a bright red solid is obtained. Chemically, this substance is:
a) Iron
b) Iron oxide
c) Sulphur
d) Iron sulphide

28 The color of zinc metal is:
a) Light grey
b) Reddish brown
c) Black
d) Light yellow

29 In our domestic electric circuit, the component which is always connected in series is:
a) Fuse wire
b) Earth wire
c) Live wire
d) Connecting wire

30 The stain used in the preparation of temporary mount of a leaf peel to observe stomata is:
a) Safranin
b) Methylene blue
c) Glycerin
d) Iodine solution

31 If a plant is kept in a room with green light, it will:
a) Respire forever
b) Photosynthesize
c) Die
d) Live for some time till it has food to respire

32 The purpose of keeping some KOH in the test tube with the germinating seeds in the conical flask in the set up to demonstrate that CO₂ is released during respiration is:
a) To absorb water from the seeds to make them dry
b) To make the air in the flask warm
c) To absorb CO₂ and create partial vacuum in the flask
d) To provide oxygen to the germinating seeds

33 To prepare a good temporary mount of the petunia leaf showing many stomata, the student should get the peel from the:
a) Tip of the leaf
b) Upper surface of the leaf
c) lower surface of the leaf
d) point of attachment of the leaf to its petiole

34 How will you connect a given set of resistors so that the equivalent resistance is increased? Give reason for your answer.

35 What would you observe when you put some aluminium pieces in copper sulphate solution?

36 Why do we use germinating seeds for the study of respiration process?