Class 8 Chemical Effects Of Electric Current CBSE Questions & Answers

Class 8 · Chemical Effects Of Electric Current

This is Science Class 8 Chemical Effects of Electric Current CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
When electrodes are immersed in water and electric current is passed the bubbles formed at positive terminal is
  • A
    Nitrogen gas
  • B
    Carbon dioxide gas
  • C
    Oxygen gas
    Correct
  • D
    Hydrogen gas
2
Live wire is covered with ____________ coloured insulation.
  • A
    Black
  • B
    White
  • C
    Red
    Correct
  • D
    Green
3
Small amount of Sulphuric acid is added to copper sulphate solution during electroplating to
  • A
    To increase acidity
  • B
    Decrease conductivity
  • C
    Increase conductivity
    Correct
  • D
    Add blue colour
4
The substance that easily allow the current to pass through it is called
  • A
    Conductor
    Correct
  • B
    Poor conductor
  • C
    Non-conductor
  • D
    Insulator
5
A coating of ________ is deposited on iron to protect it from rusting.
  • A
    Copper
  • B
    Zinc
    Correct
  • C
    Aluminium
  • D
    Silver
6
Electric bell works on the principle of
  • A
    Heating effect of electric current
  • B
    Chemical effect of electric current
  • C
    Magnetic effect of electric current
    Correct
  • D
    Electro-magnetic effect
7
Galvanizing is done on metal surface to
  • A
    Make more durable
  • B
    Protect from corrosion
    Correct
  • C
    All of these
  • D
    Increase its look
8
Which type of effect is produced by electric current passes through a conducting solution?
  • A
    Physical effect of electric current
  • B
    Heating effect of electric current
  • C
    Chemical effect of electric current
    Correct
  • D
    Magnetic effect of electric current
9
The process of depositing a thin layer of desired metal on another metal is called
  • A
    Electrolysis
  • B
    Electron decreasing
  • C
    Electric depositing
  • D
    Electroplating
    Correct
10
In bulbs electricity is converted into
  • A
    Heat energy
  • B
    Sound energy
  • C
    Mechanical energy
  • D
    Light energy
    Correct
11
Chromium plating is done on many objects like cars, kitchen stoves and bath fitting to
  • A
    Prevent corrosion and scratch resistance
    Correct
  • B
    Chromium is low cost metal
  • C
    Increase the look
  • D
    Increase the look to sell at higher price
12
A conductor having very low resistance is called
  • A
    Resistor
  • B
    Super conductor
  • C
    Good conductor
    Correct
  • D
    Insulator
13
Which of the following liquid is poor conductor of electricity?
  • A
    Distilled water
    Correct
  • B
    Alkaline solution
  • C
    Common salt solution
  • D
    Acidic solution
14
In an electric circuit bulb glows only when switch is in
  • A
    Any position
  • B
    Closed position
    Correct
  • C
    Open position
  • D
    Either open or closed position
15
Tin cane, used for storing food, is made by electroplating iron on tin because
  • A
    Tin gives shiny appearance
  • B
    Tin appear more beautiful
  • C
    Tin is less reactive than iron
    Correct
  • D
    Tin is lighter