Class 8 Science Chapter 14 MCQ

Class 8 Science Chapter 14 MCQ (Multiple Choice Questions) of Chemical Effects of Electric Current updated for new academic session 2021-2022. These multiple choice objective quiz will help the students in the preparation of school tests and terminal exams.

Prepare the entire chapter 14 of class 8 science using these objective questions with answers. All the questions are important as well as useful for a student of standard 8. These questions are prepared from the class 8 science chapter 14 NCERT Textbook only.

Class 8 Science Chapter 14 MCQ for 2021-2022

Class: 8Science
Chapter: 14Chemical Effects of Electric Current
Contents: MCQ Online Tests with Explanation

MCQ Tests with Answers for Class 8 Science Chapter 14




Q1

An electric current can produce:

[A]. Heating effect
[B]. Chemical effect
[C]. Magnetic effect
[D]. Chemical, heating, and magnetic effects.
Q2

Which of the following statement is or are correct?

[A]. The object to be electroplated is taken as negative electrode.
[B]. One of the most common applications of chemical effect of electric current is electroplating.
[C]. Small amount of a mineral salt present naturally in water makes it a good conductor of electricity.
[D]. All the above
Q3

In an activity to check the conduction of electricity through two liquids labelled A and B by using a bulb, it is observed that the bulb glows brightly for liquid B while it glows very dimly for liquid A.

[A]. Liquid A is a better conductor than liquid B
[B]. Liquid B is a better conductor than liquid A
[C]. Both liquids are equally conducting
[D]. Conducting properties of liquids cannot be compared in this manner
Q4

Read the following sentences carefully, and choose the incorrect one:

[A]. The liquids that conduct electricity are solution of acids, bases and salts in water.
[B]. Liquid which can conduct electricity is called an electrolyte.
[C]. The liquids which conduct electricity are called conducting liquids.
[D]. None of the above
Q5

In a science quiz competition, Payel is asked a question where she had to choose the statement which was/were correct?

[A]. A strong electrolyte is a liquid or solution which conducts electricity very well.
[B]. A weak electrolyte is a liquid or solution which conducts electricity to a lesser extent.
[C]. A solid electrical conductor through which an electric current enters or leaves something like a dry cell, is called an electrode.
[D]. All the above




Q6

Recently, in a science class test, you are asked a question where you have to say whether the statements are correct or not?

[A]. The positively charged electrode is called anode.
[B]. The negatively charged electrode is called cathode.
[C]. An arrangement having two electrodes kept in a conducting liquid in a vessel is called an electrolytic cell.
[D]. All the above
Q7

Which of the following metals are produced by the electrolysis of their molten compounds?

[A]. Copper and Silver
[B]. Silver and Aluminium
[C]. Aluminium and Sodium
[D]. Sodium
Q8

Which of the following types of energy can be used can be used to decompose water into its elements?

[A]. Heat energy
[B]. Light energy
[C]. Chemical energy
[D]. Electrical energy
Q9

When electric current is passed through a conducting solution, there is a change of colour of the solution. This indicates:

[A]. The chemical effect of current.
[B]. The heating effect of current.
[C]. The magnetic effect of current.
[D]. The lightning effect of current.
Q10

Badal appeared in class test but he confused to know the correct statement. Would you help him to know that?

[A]. Due to the presence of small amount of acids, rain water becomes a conductor of electricity.
[B]. Sea water is a much better conductor of electricity than drinking water.
[C]. We should never operate an electric switch or touch any working electrical appliances with wet hands.
[D]. All the above



Q11

Recently, in a science class test, you are asked a question where you have to say whether the statements are correct or not?

[A]. We can dissolve some salt in distilled water or pure water to make it a good conductor of electricity.
[B]. We can add a little of acid in distilled water or pure water to make it a good conductor of electricity.
[C]. We can add a little of a base in distilled water of pure water to make it a good conductor of electricity.
[D]. All the above
Q12

Which one of the following solutions will not conduct electricity?

[A]. Lemon juice
[B]. Vinegar
[C]. Tap water
[D]. Vegetable oil
Q13

In a quiz competition, you are asked a question where you have to choose the statement which is/ are incorrect?

[A]. The chemical decomposition produced by passing an electric current through a conducting liquid is called electrolysis.
[B]. When an electric current flow through a conducting solution, it causes a chemical reaction.
[C]. If electric current is passed through acidified water, then bubbles of oxygen gas and hydrogen gas are produced at the two electrodes immersed in it.
[D]. None of the above
Q14

Which of the following metals is used in electroplating to make objects appear shining?

[A]. Iron
[B]. Copper
[C]. Chromium
[D]. Aluminium
Q15

In the last year examination of class VIII, Rahul were asked a question where he had to choose the statement which was/were incorrect? Will you be able to answer this question?

[A]. The process of depositing a thin layer of a desired metal over a metal object with the help of electric current is called electroplating.
[B]. The chemical effect produced by an electric current depends on the nature of conducting solution and nature of electrodes.
[C]. The fresh fruits and vegetables conduct electricity to some extent due to the presence of various salt solution in them.
[D]. None of the above




Q16

Electrolytes conduct electricity due to the movement of:

[A]. Electrodes
[B]. Atoms
[C]. Electrons
[D]. Ions
Q17

The chemical reaction brought about by an electric current may produce one or more effects. Choose the correct statements:

[A]. Bubbles of a gas may be formed on the electrodes.
[B]. Deposits of metals may form on electrodes.
[C]. Changes in colour of solution may occur
[D]. All the above
Q18

Non-metals are generally non-conductors of electricity. The non-metal whose one of the forms can be used to make electrodes in electrolysis experiments is:

[A]. [A] Iodine
[B]. Carbon
[C]. Silicon
[D]. Phosphorus
Q19

Consider the following statements and choose the correct one:

[A]. Chromium metal has a shiny appearance and it does not rust.
[B]. Tin metal has a shiny appearance and it does not corrode and it is non-poisonous.
[C]. Electroplating is used to give objects made of a cheap metal a coating of a more expensive metal to make them look more attractive.
[D]. All the above
Q20

In the purification of an impure metal by using the chemical effect of electric current or electrolysis, we should not take:

[A]. A thick rod of impure metal is made positive electrode.
[B]. A thin strip of pure metal is made negative electrode.
[C]. A water-soluble salt of the metal to be purified is taken as electrolyte.
[D]. A distilled water salt of the metal to be purified is taken as electrolyte.




Q21

Which of the following can be electroplated with chromium?

[A]. Bakelite and Graphite
[B]. Graphite and Steel
[C]. Steel
[D]. Graphite and Teflon
Q22

Chemical effect of electric current is used in industries or factories for the different purposes. Choose the correct purposes:

[A]. Electroplating metals and purification of metals
[B]. Production of certain metals from the ores
[C]. Production of chemical compounds and decomposing chemical compounds
[D]. All the above
Q23

The device which can be used to detect very small current flowing in an electric circuit is:

[A]. LEAD
[B]. dB
[C]. MCB
[D]. LED
Q24

If plus sign (+) denotes the positive electrode and minus sign (-) denotes the negative electrode, then which of the following statement is correct for an iron spoon to be copper plated?

[A]. Iron spoon (+), copper plate (-), Iron sulphate electrolyte
[B]. Iron spoon (-), copper plate (+), Iron sulphate electrolyte
[C]. Copper plate (-), Iron spoon (+), Copper sulphate electrolyte
[D]. Copper plate (+), Iron spoon (-), Copper sulphate electrolyte
Q25

For electroplating an iron object with copper metal or copper plating, we should not follow the method is or are:

[A]. The iron object is made negative electrode.
[B]. The copper plate is made positive electrode.
[C]. Iron sulphate solution is taken as electrolyte.
[D]. Copper sulphate solution is taken as electrolyte.

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