Telangana SCERT Class 8 Physical Science Chapter 9 Solution – Electrical Conductivity of Liquids. Here in this post we provides Class 8 Physical Science Electrical Conductivity of Liquids Telangana State Board Solution. Telangana State Board English Class VIII Medium Students can download this Solution to Solve out Improve Your Learning Questions and Answers.
Telanagana State Board Class 8 Physical Science Chapter 9 Electrical Conductivity of Liquids Solution:
(1) Give examples for good solid conductors and liquid conductors.
Ans. Good solid conductors are – gold, silver, aluminium, copper etc..
Good Liquid conductors are –
(2) Give examples for poor solid conductors and liquid conductors.
ans. Poor solid conductors are –
dry wood, dry clothes, paper, plastic etc.
Liquid poor conductors are –
distilled water, coconut oil, kerosene etc.
(3) Give two examples for electrolyte.
Ans. Two examples for electrolyte are Sulphuric acid and Nitric acid.
(4) Draw the diagram of Electrolytic cell and explain
Explain:- Take two injection bottle and insert a copper wires and zinc strips in these two bottle. But ensure that the copper wire and zinc strips do not touch each other.
Now take a wire and connect the copper wire in one bottle with zinc plate other bottle. Now fill them with dilute sulphuric acid.
Then take a LED and attach two wires to its two terminals.
After few seconds zinc and copper wires into dilute sulphuric acid; zinc slowly begins dissolve in the sulphuric acid and also we see bubbles forming on copper rod.
The current is passed from copper to zinc rod. These rods are known as electrodes and dilute sulphuric acids is known as electrolyte.
So here we conclude that chemical energy is converted into electric energy by “electrolysis method”.
Application of concepts
Q1. Which energy is cause for glowing of bulb in electrolytic cell?
Ans. Chemical energy is cause for glowing of bulb in electrolytic cell. Electrical energy caused by chemical energy that caused the glowing of the bulb.
Q2. What do you add to distilled water for making it to conduct electricity?
Ans. Distrilled water does not allow the electric current to pass. But when distilled water contains salts or acids it allows passage of electric current means for making into conduct electricity.
Q3. Kavya observed that a discharged dry cell which kept in sun light by her father for few hours got ability to glow LED. She got many doubts and questions to raise. Can you guess those questions or doubts?
Ans. Questions are –
i) How can it happen / possible?
ii) How did the discharge cell conduct electricity?
iii) How sunlight is helpful to recharge the dry cell?
iv) Can this dry cell work forever like this?
v) WEhat type of energy is received by the dry cell.
Q5. Collect the information and make list of good conductors and bad conductors. How do you use this information in your daily life works?
Ans. The materials that allow electric current to pass through them, they are called good conductor of electricity.
Example – In general, all metals are good conductors of electricity. Such of them are – gold, silver, aluminium, copper.
The materials that do not allow current to pass through them are called bad or poor conductors of electricity.
Example – Dry clothes, paper, plasdtics, wood, rubber etc…
The good conductors has the nature of passing current through them. They used in electrical circuits. In electroplating we use metals to coat ore metal to another.
Bad conductors does not allow to pass current through them, so they are used as insulated materials on electrical wires.
Copper wire is coated by plastic to prevent from electric shocks.
Higher Order Thinking Questions
Question 1: If the key is to be coated with aluminium instead of copper,what changes do we need to make in the experiment of coating on iron key with copper?
Ans. We should change the electrolyte. Means we should change the anode.
Question 2: Is plastic coated by the process of electroplating?Why?
Ans. No, A plastic cannot be coated on metal by electroplating process an in this process only metal can be coated on another metal. So only metal is used because they conduct electricity. But plastics can not conduct electricity.
Multiple Choice Questions
(1.) Which of the following is also used in ornamentation and decoration-
Ans. Electro plating.
(2.) Pure water is-
Ans. Electric conductor.
(3.) The material which do not allow electric current to pass through it is known as-
(4.) Electro plating is possible through
(5.) One of the following is not an electrolyte
Ans. Detergent solution.