LED is used in a circuit. Explain why.

Boojho made the circuit shown in Fig. 14.10. He wanted to observe what happens when an electric current is passed through water. But he forgot to add a few drops of lemon juice to water. Will it make any difference to his observations? Explain.

An electric current is passed through a conducting solution. List any three possible observations.

Which one of the following solutions will not conduct electricity?

Vinegar is a sour liquid. State whether vinegar will conduct electricity or not.

Name two liquids which conduct electricity and two liquids which do not conduct electricity.

Fill in the following blanks with suitable words:

(a) Most liquids that conduct electricity are solutions of ..........., ......... and ............

(b) LED glows even when a ..............electric current passes through it.

(c) The passage of an electric current through a conducting solution causes.............effect.

(d) When electric current is passed through acidified water, then ........and...........are formed.

(e) The process of depositing a layer of any desired metal on another metal by means of electricity is called ..........

(f) If you pass current through copper sulphate solution, copper gets deposited on the plate connected to the ............terminal of the battery.

Are lemon juice, vinegar and tap water, conductors or insulator?

Give an activity to examine the behaviour of the following solid materials towards electricity: plastic, copper, rubber, wood, graphite.

All liquids conduct electricity. Comment.

Define cathode and anode.