InterviewSolution
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InterviewSolution
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Apparatus : Pencil, electrical wires, battery/ cell, small bulb, water, kerosene, test tube, lead pencils, etc.Procedure : Remove the lead from a pencil and arrange the apparatus as shown in the above diagram. Note your observations for the following.Flow of electric current through graphite(a) What is the colour of lead in the pencil?(b) Try to break lead with your hand.(c) Start the electric current in the circuit and observe. What did you find?(d) Take some water in a test tube. Take some kerosene in another test tube. Put lead dust in both the test tube. What did you observe? |
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Answer» (a) The colour of the lead in the pencil is black as it is made from graphite which is an all otrophic form of carbon. (b) The lead breaks easily as it is made up of graphite which is brittle in nature. (c) When we start the electric current in the circuit, the bulb in the circuit glows, indicating that the lead in the pencil is a good conductor of electricity. (d) (i) Lead dust does not dissolve in water nor in kerosene. (ii) It remains insoluble in both the test tubes. |
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