Question 1

Q1: 1. Fill in the blanks (i) Unlike poles of two magnets $\_\_\_\_$ each other, whereas like poles $\_\_\_\_$ each other. (ii) The materials that are att...

Accepted Answer

(i) Unlike poles of two magnets attract each other, whereas like poles repel each other. (ii) The materials that are attracted towards a magnet are called magnetic materials. (iii) The needle of a magnetic compass rests along the north-south direction. (iv) A magnet always has two poles.

Question 2

Q10: 10. Two ring magnets X and Y are arranged as shown in Fig. 4.16. It is observed that the magnet X does not move down further. What could be the possib...

Accepted Answer

Possible Reason: Magnet X does not move down further because there is a strong force of repulsion between magnet X and magnet Y. This occurs when the like poles of the two ring magnets are facing each other (e.g., the North pole of magnet X is facing the North pole of magnet Y, or the South pole of...

Question 3

Q11: 11. Three magnets are arranged on a table in the form of the shape shown in Fig. 4.17. What is the polarity, N or S , at the ends $1,2,3$, 4 and 6 of...

Accepted Answer

Given that end 5 is the South (S) pole. We know that unlike poles attract each other when magnets are placed end-to-end, and each magnet has both a North and a South pole. Let's determine the polarities step-by-step: 1.  End 5 is South (S). Since end 5 (S) of the bottom horizontal magnet is touching...

Question 4

Q2: 2. State whether the following statements are True (T) or False (F). (i) A magnet can be broken into pieces to obtain a single pole. (ii) Similar pole...

Accepted Answer

(i) False (F). The poles of a magnet always exist in pairs. A single North pole or a single South pole cannot exist, even if a magnet is broken into smaller pieces. (ii) True (T). Like poles (North-North or South-South) of magnets repel each other. (iii) False (F). Iron filings stick predominantly n...

Question 5

Q3: 3. Column I shows different positions in which one pole of a magnet is placed near that of the other. Column II indicates the resulting interaction be...

Accepted Answer

The completed table is as follows: Column I           Column II N - N              Repulsion N - S              Attraction S - N              Attraction S - S              Repulsion Explanation:    Like poles (N-N or S-S) repel each other.    Unlike poles (N-S or S-N) attract each other.

Question 6

Q4: 4. Atharv performed an experiment in which he took a bar magnet and rolled it over a heap of steel U-clips (Fig. 4.15). According to you, which of the...

Accepted Answer

The correct option is (i). Explanation: When a bar magnet is rolled over magnetic materials like steel U-clips, the maximum number of clips will stick to the ends of the magnet, which are its poles. Very few or no clips will stick to the middle part of the magnet. In Figure 4.15, Position A and Posi...

Question 7

Q5: 5. Reshma bought three identical metal bars from the market. Out of these bars, two were magnets and one was just a piece of iron. How will she identi...

Accepted Answer

Reshma can identify the two magnets and the iron piece by using the property of repulsion, which is the surest test for magnetism. Here is the method: 1.  Label the bars: Label the three identical metal bars as A, B, and C. 2.  Test for repulsion: Take any two bars, for example, A and B. Bring one e...

Question 8

Q6: 6. You are given a magnet which does not have the poles marked. How can you find its poles with the help of another magnet which has its poles marked?

Accepted Answer

To find the poles of an unmarked magnet using a marked magnet, we can use the principle that unlike poles attract and like poles repel. Method: 1.  Take the magnet with its poles clearly marked (e.g., North pole and South pole). 2.  Bring the known North pole of the marked magnet close to one end of...

Question 9

Q7: 7. A bar magnet has no markings to indicate its poles. How would you find out near which end its North pole is located without using another magnet?

Accepted Answer

To find the North pole of an unmarked bar magnet without using another magnet, we can utilize the property that a freely suspended magnet always aligns itself in the Earth's north-south direction. Method: 1.  Suspend the magnet: Tie a thread exactly at the middle of the bar magnet and suspend it fro...

Question 10

Q8: 8. If the earth is itself a magnet, can you guess the poles of earth's magnet by looking at the direction of the magnetic compass?

Accepted Answer

Yes, we can guess the poles of Earth's magnet by observing the direction a magnetic compass needle points. Explanation: 1.  A magnetic compass needle is itself a small magnet, with a North-seeking pole (usually marked red) and a South-seeking pole. 2.  When a compass is placed on Earth, its North-se...

Question 11

Q9: 9. While a mechanic was repairing a gadget using a screw driver, the steel screws kept falling down. Suggest a way to solve the problem of the mechani...

Accepted Answer

The mechanic can solve the problem of falling steel screws by magnetizing the tip of the screwdriver. Method: 1.  Take a permanent bar magnet. 2.  Rub one pole of the bar magnet (e.g., the North pole) along the tip of the steel screwdriver, always moving in the same direction, from the handle toward...

NCERT Solutions