Q1. Fill in the blanks.
i. Most liquids that conduct electricity are solutions of ________, ________ and _________.
ii. The passage of an electric current through a solution causes ______________ effects.
iii. If you pass current through copper sulphate solution, copper gets deposited on the plate connected to the ___________ terminal of the battery.
iv. The process of depositing a layer of any desired metal on another material by means of electricity is called ________________.
Q2. State True (T) or False (F).
i. A piece of fresh potato does not conduct electricity. ____
ii. LED glows even when a low electric current passes through it. ____
iii. The passage of an electric current through a conducting solution causes chemical effect. ____
iv. Materials such as rubber plastic and wood conduct electricity. ____
Q3. Which metal is electroplated on bathroom fittings?
Q4. Name any one metal which is purified by using the chemical effect of current (or electrolysis).
Q5. Do liquids also conduct electricity?
Q6. Give one example of the chemical effect of electric current.
Q7. How is water decomposed into hydrogen and oxygen?
Q8. Name some liquids which conduct electricity.
Q9. Name some liquids which do not conduct electricity.
Q10. State whether vinegar and lemon juice will conduct electricity or not.
Q11. What is electroplating?
Q12. What happens to a compass needle kept nearby when current flows in a wire?
Q13. Name a device which glows even when a weak electric current passes through it.
Q14. Which is the polluting waste generated by electroplating factories?
Q15. What is the advantage of using LED in testing the electrical conductivity of liquids?
Q16. Does pure water conduct electricity? If not, what can we do to make it conducting?
Q17. Name two metals which are usually electroplated on cheaper metals for making jewelry (or ornaments).
Q18. Which effect of electric current is utilized for detecting the flow of current through a solution when a compass is used?