Activity 11.7 Class 8 Science Chapter 11 Solution

In this post, you will find NCERT Science Class 8 Chapter 11 Force and Pressure activity 11.7 with a complete explanation and conclusion. After reading this, you will be able to answer the questions based on the activity. After reading activity 11.6, you should go through the given activity given below.

You are suggested to study NCERT activity 11.7 class 8 science explanation with a conclusion so that you can attempt questions based on activity 11.7 Class 8 science.

Activity 11.7 Class 8 Science

 ·     Take a plastic straw and cut it into nearly two equal pieces.

·      Suspend one of the pieces from the edge of a table with the help of a piece of thread as shown in the figure.

·      Now hold the other piece of straw in your hand and rub its free end with a sheet of paper.

·     Bring the rubbed end of the straw near the suspended straw.

·     Make sure that the two pieces do not touch each other.

·     What do you observe?

·     Next, rub the free end of the suspended piece of straw with a sheet of paper.

·      Again, bring the piece of straw that was rubbed earlier with paper near the free end of the suspended straw.

·     What do you observe now?

Activity showing Electrostatic force

Observation and explanation 

When the end of the straw is rubbed with a sheet of paper, it acquires an electrostatic charge. When it is brought near the end of the suspended straw, it attracts the suspended straw. Such a straw is an example of a charged body.

The force exerted by a charged body on another charged or uncharged body is known as electrostatic force. The electrostatic force acts between two tow bodies even when the bodies are not in contact.

Now, the end of the suspended straw is rubbed with a sheet of paper, and the end of the free straw that was rubbed earlier is brought near it. Both the straws repel each other because they have the same charge.

The electrostatic force, therefore, is another example of a non-contact force.

Conclusion 

This activity explains electrostatic force which is a non-contact force.

Frequently asked questions

   1. What is electrostatic force class 8 science?

Ans.- The force exerted by a charged body on another charged or uncharged body is known as electrostatic force.

   2. Electrostatic forces act between:

 A.Two Charged particles

B charged and Uncharged particles

C Particles with opposite charge

D All the above

Correct answer-  (D)

   3. How is electrostatic force a non-contact force

Ans.- Electrostatic force is a non-contact force because it comes into effect even when the bodies are not in contact with each other. They pull or push on objects without touching them.

   4. Is electrostatic force an example of noncontact force?

Ans-  Yes, an electrostatic force is an example of a non-contact force because the two bodies push or pull without touching one another.

   5. Give 5  examples of electrostatic force.

Ans – following are the examples of electrostatic force-

   1. When we rub a comb in our head, it produces a charge which attracts pieces of paper. It’s an electrostatic charge.

   2. When a balloon is rubbed with hair, it attracts the other balloon.

   3. Lightening is an example of electrostatic force.

   4. When we put off woolen clothes after some time, they produce sound and light.

   5. When we iron silk or cotton clothe and bring them near our body, they cling to our body.

Related Topics

1. Activity 11.8

2. Activity 11.6