give the chemical questions
chapter electric current and its chemical effects
Answers
Answer:
giving 20 questions
Explanation:
Question 1.
What are good conductors?
Answer:
The substances that conduct electricity through them are called good conductors.
Question 2.
What are insulators or poor conductors?
Answer:
The substances that do not conduct electricity through them are poor conductors or insulators.
Question 3.
Give four examples of conductors.
Answer:
Copper, iron, aluminium and brass.
Question 4.
Give four examples of insulators.
Answer:
Air, wood, rubber and plastic.
Question 5.
Name two metal objects which have a coating of another metal.
Answer:
Handlebars of bicycles, bathroom taps.
Question 6.
What do we get on electrolysis of acidified water?
Answer:
Hydrogen and oxygen gas.
Question 7.
Is air a bad or good conductor?
Answer:
A bad conductor.
Question 8.
Which metal is plated on handle bars of cycles and rim of wheels?
Answer:
Chromium
Question 9.
What is the full form of LED?
Answer:
Light Emitting Diode.
Question 10.
How do we check the electric current?
Answer:
We check the electric current by using a tester.
Question 11.
Which part of an atom is responsible for flow of current?
Answer:
Electron
Question 12.
Why do most liquids conduct electricity?
Answer:
Due to the presence of ions in them, most liquids conduct electricity.
Question 13.
An LED is more efficient device than a bulb. Why?
Answer:
LED is more efficient because it can glow even when a weak or less current flows through it.
Question 14.
Do lemon juice or vinegar conduct electricity?
Answer:
Yes, they conduct electricity.
Question 15.
How is conductivity of liquids tested?
Answer:
By using a tester.
Question 16.
Is water from taps, handpumps, wells and ponds a good conductor?
Answer:
Yes, water from these sources is a good conductor.
Question 17.
What makes distilled water a good conductor?
Answer:
Salts when mixed with distilled water make it a good conductor.
Question 18.
Why is a layer of zinc coated over iron?
Answer:
To prevent iron from corrosion and rust.
Question 19.
Will the solution of sugar in distilled water conduct electricity?
Answer:
No
Question 20.
Why is tin electroplated on iron to make cans used for storing food?
Answer:
Tin is less reactive than iron. Tin coating prevents food from coming in contact with iron and thus pre¬vents it from getting spoiled or corroded.