Chemical effects of electric current work sheet
Answers
Explanation:
CBSE Class 8 Science Worksheet
Chemical effects of Electric Current
1. Choose the correct answer: Which metal is electroplated on iron for making cans for storing food and drinks?
A) Tin
B) Zinc
C) Chromium
D) Aluminium
2. Choose the correct answer: Small amount of Sulphuric acid is added to copper sulphate solution during electroplating to ______________________.
A) To increase resistivity
B) To increase conductivity
C) To decrease conductivity
D) To increase acidity
3. Choose the correct answer: A metal which is released in the electrolysis of a salt will be deposited on the ____________________.
A) Anode
B) Cathode
C) On the sides of the container
D) None of these
4. State True or False: Electic bell works on heating effect of electric current.
A) true
B) false
5. Choose the correct answer: The device which is used to measure electric current is ______________________.
A) Ammeter
B) Voltmeter
C) Ohmmeter
D) galvanometer
6. Fill in the blanks: The bulb glows when electric current passes through it because of ___________ effect of electric current.
7. What substances can be added to distilled water in small amounts to make it a good conductor of electricity?
8. Which of the following has the highest conductance?
A) Conductor
B) Insulator
C) Semi- conductor
D) None of these
9. Fill in the blanks: _____________ is the process of depositing a thin layer of another metal like zinc to protect from corrosion.
10. Fill in the blanks: ___________ is connected to the positive terminal of a battery.
11. Choose the correct option: Electrolytes conduct electricity due to the movement of _________.
A) electrodes
B) atoms
C) ions
D) None of these
12.
Equal masses of H2, O2 methane have been taken in a container of volume V at temperature 27 degree centigrade in identical conditions. The ratio of the volumes of gases H2:O2:CH4 would be
A)
8:16:1
B)
16:8:1
C)
16:1:2
D)
8:1:2
13. Why should electrical appliances never be handled with wet hands?
14. Fill in the blanks: In ___________ cell , zinc and copper plates are dipped in separate solution.
15. Which of the following metal is not extracted by electrolysis?
A) Iron
B) Copper
C) Aluminium
D) Sodium
16. What happens when a compass needle is brought near a current carrying wire?
17. Fill in the blanks: ________________ of electric current is utilized when a thin layer of chromium metal is deposited on an iron tap.
18. Fill in the blanks: ___________ glows even when a weak electric current passes through it.
19. State True or False: Adding lemon in water,makes it a good conducter of electricity.
A) true
B) false
20. Choose the correct answer: The decomposition of an electrolyte when electricity is passed through it, is called ________________.
A) Anodizing
B) Electroplating
C) Conduction
D) Electrolysis
CBSE Class 8 Science Worksheet
Chemical effects of Electric Current
Answers
1. Option A 2. Option B 3. Option B 4. Option B 5. Option A
6. heating 7. Acids, bases and salts. 8. Option A
9. Galvanization 10. Anode 11. Option C 12. Option A
13. Because water is a good conductor of electricity and water conducts electric current to the body which can result in electric shock. 14. Voltaic 15. Option A
16. The needle deflects. 17. Chemical effect 18. LED 19. Option A 20.OptionD
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