Class 8 Science

Chemical Effects of Electric Current

Extra Questions

Multiple Choice Questions

Question 1: Electric poles are coated with a layer of which metal?

  1. Chrmomium
  2. Zinc
  3. Silver
  4. Aluminium

Answer: (b) Zinc

Question 2: Sanitary fittings are generally coated with a layer of which metal?

  1. Chromium
  2. Zinc
  3. Silver
  4. Aluminium

Answer: (a) Chromium

Question 3: Which of the following is a bad conductor of electricity?

  1. Tap water
  2. Lemon juice
  3. Vinegar
  4. Sugar solution

Answer: (d) Sugar solution

Question 4: Which of the following is a good conductor of electricity?

  1. Distilled water
  2. Cooking oil
  3. Tap water
  4. Sugar solution

Answer: (c) Tap water

Question 5: Chemical effect of electric current is primarily used for which of the following?

  1. Electroplating
  2. Separating oxygen
  3. Separating hydrogen
  4. Separating gold

Answer: (a) Electroplating

Question 6: Which of the following will work best as a tester for electric current?

  1. Bulb
  2. LED
  3. CFL
  4. Magnetic compass

Answer: (d) Magnetic compass

Question 7: Which material is used for making the central rod in an electric cell?

  1. Copper
  2. Carbon
  3. Aluminium
  4. Iron

Answer: (b) Carbon

Question 8: Which scientist was the first to show electrolysis of water?

  1. Oersted
  2. William Nicholson
  3. Michael Faraday
  4. Galileo

Answer: (b) William Nicholson

Very Short Answer Type Questions

Question 1: What do you mean by good conductors of electricity?

Answer: Electric current can easily pass through some materials. Such materials are called good conductors of electricity, e.g. iron, copper, silver, aluminium, gold, etc.

Question 2: What do you mean by bad conductors of electricity?

Answer: Electric current cannot pass easily through some materials. Such materials are called bad conductors of electricity, e.g. rubber, wood, asbestos, plastic, etc.

Question 3: What is electroplating?

Answer: The process of depositing a layer of a desired metal on any other material by means of electrolysis is called electroplating.

Question 4: Chemical effect of electric current is also known by which term?

Answer: Electrolysis

Question 5: What is galvanization?

Answer: Applying a layer of zinc on an article by electroplating is called anodizing.

Question 6: What is gold plating?

Answer: Applying a layer of gold on any material by electroplating is called gold plating.

Question 7: During electrolysis of water, oxygen gas is deposited at which electrode?

Answer: Positive terminal or anode

Question 8: During electrolysis of water, hydrogen gas is deposited at which electrode?

Answer: Negative terminal or cathode