NCERT Solutions For Class 8 Science Chapter 11 Chemical Effects Of Electric Current VSAQs

NCERT Solutions For Class 8 Science Chapter 11 Chemical Effects Of Electric Current VSAQs

Question 1. It is dangerous to touch an electrical appliance with wet hands. Explain why?
Answer: A Wet hand acts as a good conductor. So, we feel an electric shock when we touch an electrical appliance with wet hands.

Question 2. Paheli and Boojho want to remind you that one should not experiment with the electric supply from the mains or a generator or an inverter. Why ?
Answer: The electrical supply which comes in our domestic main electrical line is about 120 V. We should not use this High voltage electricity for an experiment. This can cause serious injuries or instant death.

NCERT Class 8 Science Chapter 11 Chemical Effects of Electric Current VSAQs

Question 3. Sometimes we see that the liquid is conducting, but the bulb may not glow. Why?
Answer: The bulb does not glow because the current through it is too weak

Question 4. The bulb glows when the electric current passes through it. Explain why?
Answer: Due to the heating effect of the current, the filament of the bulb gets heated to a high temperature, and it starts glowing. However, if the current through a circuit is too weak, the filament does not get heated sufficiently, and it does not glow.

Question 5. When a compass needle is brought near a current-carrying wire, what happens?
Answer: When a compass needle is brought near a current-carrying wire, the needle deflects.

Question 6. Can we make another tester v/hich can detect a weak current?
Answer: Yes. we can use another effect of an electric current to make another kind of tester, i.e. magnetic effect of electric current.

Question 7. Do poor conductors also allow electricity to pass under certain conditions?
Answer: Yes, poor conductors can conduct electricity under certain conditions, like wet wood.

NCERT Solutions for Chemical Effects of Electric Current Chapter 11

Question 8. Give the names of these substances, which, when added to distilled water, make them good conductors of electricity
Answer: Acids, bases, and salts are those substances that, when added to distilled water, make it a good conductor of electricity.

Question 9. Give the names of the three effects of electric current.
Answer: The three effects of electric current are

1. The heating effect of the current
2. Magnetic effect of current
3. Chemical effect of the current

Question 10. An electric current is passed through a conducting solution. List any three possible observations.
Answer: Three possible observations are

1. The colour of the solution may change depending on the electrodes.
2. The temperature of the solution may increase.
3. Bubbles near the electrodes can be seen.

Class 8 Chapter 11 Chemical Effects of Electric Current VSAQs

Question 11. After doing the electroplating activity, Paheli interchanged the electrodes and repeated the activity. What do you think she would observe this time?
Answer: Paheli will observe the gas bubbles.

Question 12. In the electroplating process, what about the loss of copper from the solution?
Answer: An equal amount of copper gets dissolved in the solution from anode, thus the loss ofcopper from the solution is restored.

Question 13. The process of depositing a layer of any desired metal on another material employing electricity is called
Answer: Electroplating

Question 14. When the free ends of n tester arcs are dipped into solutions, the magnetic needle shows deflection. Can you explain the reason?
Answer: When the free ends of a tester arc are dipped into a solution, the liquid between the two ends allows the electric current to pass, and the circuit of the tester becomes complete.

NCERT Solutions for Chemical Effects of Electric Current VSAQ

Also, when the current passes through the tester, it establishes a magnetic effect, and hence, the magnetic needle shows deflection. In other words, we can say that the solution is a good conductor ofelectricity, so the needle gets deflected.