TextBook Solutions for Uttarakhand Board Class 8 Science Chapter 14 Chemical Effects Of Electric Current

Most liquids that conduct electricity are solutions of________, ________ and ________.

The passage of an electric current through a solution causes _________ effects.

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

The process of depositing a layer of any desired metal on another material object by means of electricity is called _______________.

When the free ends of a tester are dipped into a solution, the magnetic needle shows deflection. Can you explain the reason?

Name three liquids, which when tested in the manner shown in figure, may cause the magnetic needle to direct.

The bulb does not glow in the setup shown in figure. List the possible reasons. Explain your answer.

 

A tester is used to check the conduction of electricity through two liquids, labeled A and B. It is found that the bulb of the tester glows brightly for liquid A while it glows very dimly for liquid B. You would conclude that

• liquid A is a better conductor than liquid B.

• liquid B is a better conductor than liquid A.

• both liquids are equally conducting.

• conducting properties of liquid cannot be compared in this manner.

Does pure water conduct electricity? If not, what can we do to make it conducting?

In case of fire, before the firemen use the water hoses, they shut off the main electrical supply for the area. Explain why they do this.