CBSE Science Class 8
Chemical Effects of Electric Current
Chemical Effects of Electric Current - Chapter Wise CBSE Solved Question and Answer Based On NCERT
Very Short Q&A:
Q1: Name some materials which are good conductors of electricity.
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Ans:
Copper, aluminium, etc.
Q2: Name some materials which are bad conductors of electricity.
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Ans:
Wood, rubber, plastics etc.
Q3: What is the purpose of a tester?
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Ans:
To test whether a particular material allows the electric current to pass through it or not.
Q4: Does lemon juice or vinegar conduct electricity?
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Q5: Which is good conductor a copper wire or a wooden board?
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Q6: Dissolve some salt in distilled water, the resulting solution will be good conductor of electricity or bad conductor?
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Q7: Why distilled water is poor conductor of electricity?
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Because distilled water is free of salts.
Q8: What effect does the current produce when it flows through a conducting solution?
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Current causes chemical reactions when it flows through a conducting solution?
Q9: Define electroplating.
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The process of depositing a layer of any desired metal on another material by means of electricity is called electroplating.
Q10: Why electroplating are used?
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Electroplating is mostly used in industry for coating of metal objects with a thin layer of different metal.
Q11: How tin cans are made?
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By electroplating tin into iron.
Q12: How iron can be protected from corrosion?
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A coating of zinc is deposited on iron to protect iron from corrosion.
Q13: Which is more reactive tin or iron?
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Q14: Most liquid that conducts electricity are solutions of acids, ________ and __________.
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Q15: The passage of an electric current through a solution causes ________________ effect.
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Q16: Which of the following is good conductor of electricity
- copper
- wood
- distilled water
- None of these
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Q17: Liquid conducts electricity .True/ False.
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Q18: Why rubber and plastics do not conduct electricity?
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Ans:
Because they do not allow electric current to pass through it.
Q19: Why it is dangerous to touch an electrical appliance with wet hand?
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Because water can conduct electricity.
Q20: In a set up to test conduction of electricity why the bulb glows when the electric current passes through it?
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Because of the heating effects of current, the filament of the bulb gets heated to a high temperature and it starts glowing.
Q21: What is the full form of LED?
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Light emitting diode.
Q22: What is LED?
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It is a semiconductor light source, use to detect weak current in the circuit.
Q23: LED glows even when weak electric current flows through it. True/False.
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Q24: Electric current produces ______________field.
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Q25: Is air a poor conductor of electricity under all conditions?
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Q26: What do you mean by salt solution?
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Ans:
Salt dissolved in distilled water forms salt solution.
Q27: The passage of an electric current through a conducting solution causes _________________.
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Q28: What is the name of process in which one metal has coating of another metal?
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Q29: Why chromium plating is done on car parts?
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Because chromium does not corrode.
Q30: Name some objects around you that are electroplated.
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Ans:
Kitchen gas burner, bath taps, bicycle handle bars etc.
Q31: We add small amount of dilute hydrochloric acid to distilled water, the resulting solution will be a good conductor or poor conductor?
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Q32: We add small amount of sugar to distilled water, the resulting solution will be a good conductor or poor conductor?
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Q33: We add small amount of caustic soda to distilled water, the resulting solution will be a good conductor or poor conductor?
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Q34: The path through which an electric current flows is called
- Electric path
- Electric relay
- Short circuit
- Electric circuit
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