Class 8 Chemical Effects of current
Multiple Choice Questions (MCQs)
- Which of the following is an insulator?
(a) Human body
(c) Pure water
- In electroplating, the object to be electroplated is made:
- The extraction of metals from their ores by electrolysis is called:
- The refining or purification of metals by passing electric current is called:
- Carbon rods, used as electrodes are made up of:
- Which of these are the applications of electrolysis?
(a) Metal Extraction
(d) All these
- In an electrolytic cell, the electrode which is connected to the positive terminal of the battery is called:
- Which of these is plated on the iron to prevent it from chemically reacting with food?
- Out of the following, which metal is used to electroplate iron to make it shining and rust resistant?
Fill in the blanks:
- Electroplating is based on the —chemical—-effect of electric current.
- Wood is a—bad— conductor of electricity.
- Pencil lead is a.
- The flow of electrons is called—current—.
- Tap water is a—good conductor of electricity.
- Tap water conducts electricity because it has dissolved in it.
- The process used to purify a metal is called —-electroplating.
State whether ‘True’ (T) or ‘False’ (F):
- Chromium corrodes easily. F
- The sugar solution is an electrolyte. F
- Cations are negatively charged particles. T
- Electrolytes produce ions when dissolved in water. T
- A cycle rim is made of iron that is electroplated with chromium. T
- Touching an electrical appliance with wet hands can be very dangerous. T