CHEMICAL EFFECTS OF ELECTRIC CURENT
ONE MARK MCQs
1. Veena has read that some substances are good conductors of electricity where as some are bad conductors. Among the following which substance is good conductor of electricity?
a) Copper
b) Silver
c) Iron
d) All of the above (✓)
2. Today Rohit came to know that in the ancient times people used a device to detect direction. What was that device called?
a) Voltmeter
b) Ammeter
c) Magnetic Compass (✓)
d) All of the above
3. Manish today read about various effects of electric current. Electric bulb works on which effect of electric current?
a) Heating effect (✓)
b) Magnetic effect
c) Chemical effect
d) All of the above
4. Neeta's mother today brought gold plated silver jewelry. What is the process of plating one metal on another metal called?
a) Vaporization
b) Electroplating (✓)
c) Distillation
c) All of the above
5. Dhruv was very happy to see traffic signals in the city. What kinds of lights are used in traffic signals?
a) Tungsten bulb
b) LED bulb (✓)
c) Neon bulb
d) None of the above
6. Meenakshi broke a dry cell today. She got a black colored rod from it. What is this rod called?
a) Electrode (✓)
b) Electrolyte
c) Insulator
d) All of the above
7. Heera singh is surprised that the flow of electric current breaks the water into hydrogen and oxygen. Can you tell me that due to which effect of current this happens?
a) Heating effect
b) Chemical effect (✓)
c) Magnetic effect
d) All of the above
8. Today Baljinder saw in science lab that lemon juice is good conductor of electricity. Among the following which is good conductor of electricity?
a) Vinegar
b) Tap water
c) Tomato juice
d) All of the above (✓)
9. Electricity repair is going on at sewak's house. He saw that handles of electrical repairing tools are made up of plastic. What is the reason for this?
a) Plastic is good conductor of electricity.
b) Plastic is bad conductor of electricity. (✓)
c) Plastic generates electricity.
d) None of the above.
10. Pankaj knows that pure water is bad conductor of electricity. If you dissolve salt in water what will happen?
a) Water will become good conductor of electricity (✓)
b) Water will become bad conductor of electricity.
c) Water will neither become good conductor nor bad conductor.
d) None of the above.
11. Sanjeev noted that there is layer of another metal on iron vehicles. Why is this done?
a) To prevent rusting.
b) To increase the strength of iron.
c) To make the surface shiny.
d) All of the above. (✓)
12. Rupinder and Noor attached one end of a LED bulb with a cell and other with a screwdriver. If screwdriver is made of iron then what will happen if it is attached to the other terminal of cell?
a) Bulb will glow(✓)
b) Bulb will not glow
c) Can't say anything
d) Bulb will blink.
13. Robin stood near motorcycle and asked his father that the rim of wheel is made of iron but why is it more shiny then normal iron?
a) Due to more driving
b) Motorcycle is new
c) There is plating of another metal on iron (✓)
d) Can't say anything.
14. On passing electricity through copper sulphate solution, copper will deposits on the plate connected to which terminal of battery?
a) Positive terminal
b) Negative terminal (✓)
c) Both terminals
d) None of the both.
15. While electroplating of copper which liquid is added to make the copper sulphate solution more conducting?
a) Sulphuric acid (✓)
b) Sodium Hydroxide
c) Sugar solution
d) Kerosene oil
16. Out of below given options which is the use of magnetic effect of current?
a) Electroplating
b) Electric Iron
c) Electric Bulb
d) Electric Bell (✓)
17. Rajesh's father brought a LED from market. Rajesh noted that one wire of LED is long and another is short. The Long wire is connected to which terminal of battery?
a) Positive terminal (✓)
b) Negative terminal
c) Neither positive nor negative
d) Any terminal
18. Pari's father told her that air is bad conductor of electricity. But Pari has seen the lighting moving toward ground very fast in rainy season even though it was not raining at that time. What is then reason for this?
a) Due to low temperature
b) Due to more humidity in air (✓)
c) Due to high wind speed
d) All of the above
19. Some articles e.g. some parts of cars, taps and gas burners have plating of chromium on them.Among the given statements which is not correct for chromium?
1. Chromium has shine. 2. Chromium does not corrode. 3. Chromium is very cheap.
a) 1 (✓)
b) 2 (✓)
c) 3
d) All of the above.
20. Which object can be used instead of iron nail in given circuit so that flow of current remain uninterrupted?
a) Graphite (✓)
b) Plastic
c) Wood
d) Rubber
More Question
Q1. Explain the meaning of a good and bad conductor of electricity with an example.
Q2. Can liquids conduct electricity ? If yes, how ?
Q3. Explain an activity to demonstrate the conductance of electricity in a liquid along wit a labeled diagram.
Q4. Identify the following liquids as conducting or poorly conducting – Lemon juice, vinegar, tap water , distilled water, vegetable oil, milk.
Q5. We should not touch electrical equipment with wet hands. Explain why ?.
Q6 Does distilled water conduct electricity ? If no, then what can be done to make it a conductor of electricity.
Q7. Define the terms : Electrolyte, Electrolysis, Anode and Cathode.
Q8. Give reasons –
a. Bridges are made of galvanized iron.
b. Chromium plating is done on car parts, bath taps, wheel rims, etc.
c. Electrolysis of water is carried out using acidulated water.
Q9. List the changes that occur when electric current passes through a conducting solution.
Q10. What is electroplating ? List some applications of electroplating.
Click on link below to download CBSE Class 8 Science Chemical Effects of Electric Current Assignment Set D
