Chemical Effects of Electric Current – Very Short Answer Type Questions
CBSE Class 8 Science – Chapter Wise Study Materials Based on NCERT
Chapter 14: Chemical Effects of Electric Current – Very Short Answer Questions
Suitable for:
Annual Examination • Periodic Tests • Class Tests • Pre-Board / School Level Board Exam Pattern
These Very Short Questions with Answers are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 8 board exams standard.
Below is a topic-wise set of 50 Very Short Answer Type Questions from
Chapter 14: Chemical Effects of Electric Current with clear and easy-to-understand answers
to help students revise quickly and effectively.
Very Short Answer Type Questions – Chapter 14
A. Conductors, Insulators and Conducting Liquids
Q1.What is a conductor?
A conductor is a material that allows electric current to pass through it easily.
Q2.Give any two examples of solid conductors.
Copper and aluminium are two examples of solid conductors.
Q3.What is an insulator?
An insulator is a material that does not allow electric current to pass through it easily.
Q4.Name two materials used as electrical insulators.
Plastic and rubber are commonly used as electrical insulators.
Q5.Define a conducting liquid.
A conducting liquid is a liquid that allows electric current to pass through it, usually due to ions present in it.
Q6.Give one example of a liquid that conducts electricity.
A solution of common salt in water conducts electricity.
Q7.Name one liquid that is a poor conductor of electricity.
Distilled water is a poor conductor of electricity.
Q8.How can distilled water be made a good conductor?
By dissolving a small amount of acid, base or salt in it, distilled water becomes a good conductor.
Q9.Is tap water a good conductor or a poor conductor? Why?
Tap water is a good conductor because it contains dissolved salts and minerals that provide ions.
Q10.Name two liquids that generally do not conduct electricity.
Kerosene and cooking oil generally do not conduct electricity.
B. Testing Conductivity – LED, Bulb and Magnetic Effect
Q11.Which device is often used in this chapter to test weak electric currents?
An LED (Light Emitting Diode) is used to test weak electric currents.
Q12.Why is LED preferred over a bulb to test conduction in liquids?
Because an LED can glow even with a very small current, while an ordinary bulb may not glow with weak currents.
Q13.What does it indicate if the bulb or LED glows in a circuit containing a liquid?
It indicates that the liquid conducts electricity and is a conductor.
Q14.What does it indicate if the bulb does not glow in the circuit?
It indicates that the liquid is a poor conductor or does not allow enough current to flow.
Q15.How can a compass needle be used to test whether current is flowing?
If a compass needle placed near a current-carrying coil deflects, it shows that current is flowing through the circuit.
C. Chemical Effects of Electric Current – Basics
Q16.What is meant by the chemical effect of electric current?
The chemical effect of electric current is the chemical change produced in a conducting solution when current passes through it.
Q17.Name any one change that may occur due to the chemical effect of current.
One change is the formation of gas bubbles at the electrodes.
Q18.What is an electrolyte?
An electrolyte is a conducting liquid or solution through which electric current can pass.
Q19.What are electrodes?
Electrodes are conducting rods or plates (metal or graphite) dipped in an electrolyte and connected to a battery.
Q20.What is an anode?
An anode is the positive electrode connected to the positive terminal of the battery.
Q21.What is a cathode?
A cathode is the negative electrode connected to the negative terminal of the battery.
Q22.Which electrode is connected to the positive terminal of the battery?
The anode is connected to the positive terminal of the battery.
Q23.Which electrode is connected to the negative terminal of the battery?
The cathode is connected to the negative terminal of the battery.
D. Observations in Chemical Effects
Q24.Give any two effects that may be observed when current passes through a solution.
We may observe gas bubbles at electrodes and deposition of a metal on an electrode.
Q25.What happens to the colour of copper sulphate solution when copper electrodes are used and current is passed?
The blue colour of copper sulphate solution generally remains nearly the same when copper electrodes are used.
Q26.In the copper sulphate experiment, on which electrode is copper deposited?
Copper is deposited on the cathode (negative electrode).
Q27.In the same experiment, what happens to the anode?
The anode (copper plate) slowly gets thinner as copper leaves it and goes into the solution as ions.
Q28.What does the deposition of copper on the cathode show?
It shows that a chemical change is taking place due to the electric current, i.e., a chemical effect of current.
E. Electrolysis – Simple Idea
Q29.What is electrolysis?
Electrolysis is the chemical decomposition of a substance in solution when electric current is passed through it.
Q30.What happens to positive ions in an electrolyte during electrolysis?
Positive ions move towards the cathode during electrolysis.
Q31.What happens to negative ions in an electrolyte during electrolysis?
Negative ions move towards the anode during electrolysis.
Q32.Name the charged particles which help in conduction of electricity in liquids.
Ions (positive and negative) help in conduction of electricity in liquids.
F. Electroplating – Definition and Principle
Q33.What is electroplating?
Electroplating is the process of depositing a thin layer of one metal over another metal object using electric current.
Q34.Which electrode is the object to be electroplated made?
The object to be electroplated is made the cathode (negative electrode).
Q35.The metal to be coated is used as which electrode during electroplating?
The metal to be coated is used as the anode (positive electrode).
Q36.What should be taken as electrolyte in electroplating?
A solution of a salt of the metal to be deposited should be taken as electrolyte (e.g., copper sulphate for copper plating).
Q37.Give one example where electroplating is used to protect metal from corrosion.
Iron cans are electroplated with tin to protect them from corrosion.
Q38.Give one example where electroplating is used to make objects look attractive.
Artificial jewellery is electroplated with gold to make it look attractive.
G. Applications and Examples of Electroplating
Q39.Why are cycle and car parts often chrome plated?
They are chrome plated to prevent corrosion and give a shiny, decorative appearance.
Q40.Why is electroplating economically useful?
It allows a cheap metal to be coated with a small amount of costly metal, reducing cost while improving appearance and resistance.
H. Good and Poor Conductors – NCERT Focus
Q41.Do all metals conduct electricity?
Yes, all metals are generally good conductors of electricity.
Q42.Is the human body a conductor or an insulator?
The human body is a conductor of electricity.
Q43.Is pure distilled water a good conductor of electricity?
No, pure distilled water is a poor conductor of electricity.
Q44.Why is tap water more conducting than distilled water?
Tap water contains dissolved salts and minerals which provide ions, making it more conducting than distilled water.
I. Safety and Precautions
Q45.Why are we advised not to touch electrical appliances with wet hands?
Because water with dissolved salts conducts electricity and may cause electric shock if we touch appliances with wet hands.
Q46.What type of source (mains or battery) should be used in school experiments on chemical effects?
Only small cells or batteries should be used, not mains electricity, for safety.
J. Miscellaneous Conceptual Questions
Q47.What happens to the mass of the cathode during copper electroplating?
The mass of the cathode increases because copper is deposited on it from the solution.
Q48.What happens to the mass of the anode during copper electroplating?
The mass of the anode decreases as copper atoms leave it and enter the solution as ions.
Q49.Give one reason why electroplating should be carefully controlled.
It should be controlled to ensure an even, thin coating and to avoid wastage of the expensive metal.
Q50.How does electroplating show that electric current can produce chemical changes?
In electroplating, current causes a new layer of metal to form on an object, which is a clear chemical change, proving the chemical effect of electric current.
These 50 topic-wise Very Short Answer Questions with answers cover all key ideas of
Chapter 14: Chemical Effects of Electric Current from the NCERT Class 8 Science textbook
and support fast, effective revision for CBSE Class 8 board exams standard.