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प्रश्न
Make four electromagnets with 20, 40, 60 and 80 turns. Connect them one by one to a battery of 2 cells. Bring the electromagnet near a box of pins. Count the number of pins attracted by it. Compare the strengths of the electromagnets.
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उत्तर
Experiment Steps and Observations:
-
Materials Needed:
- Coils with 20, 40, 60, and 80 turns.
- Battery (2 cells).
- Box of pins.
-
Procedure:
- Wind the coils around an iron core to create electromagnets.
- Connect each coil to the battery one by one.
- Bring each electromagnet near the box of pins and count the pins attracted.
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Observations:
- 20 turns: Attracts a small number of pins.
- 40 turns: Attracts more pins than the 20-turn coil.
- 60 turns: Attracts even more pins.
- 80 turns: Attracts the most pins.
Result:
| Number of Turns | Pins Attracted |
| 20 | Few pins |
| 40 | More pins |
| 60 | Even more pins |
| 80 | Most pins |
Conclusion:
The strength of the electromagnet increases with the number of turns in the coil. Therefore, the electromagnet with 80 turns is the strongest, followed by those with 60, 40, and 20 turns.
Visual Representation:
The provided image shows the electromagnets with different turns and the pins they attract, illustrating the increasing strength with more turns.
संबंधित प्रश्न
What device reverses the current?
The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a galvanometer. The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was ______.
A coil is connected to a galvanometer. When the N-pole of magnet is pushed into the coil, the galvanometer deflected to the right. What deflection, if any, is observed when:
the magnet is a rest in the coil?
In the Activity shown below, how do we think the displacement of rod AB will be affected if
- current in rod AB is increased
- a stronger horse-shoe magnet is used
- length of the rod AB is increased?
|
(b) State whether the following statements are true or false:
(i) Magnetic poles exist in pairs.
(ii) Global warming is a desirable aspect of the intensified greenhouse effect.
(ii) Global warming is a desirable aspect of the intensified greenhouse effect.
Answer the following question:
State the effect on the magnetic needle in Oersted’s experiment when:
(a) the current is passed through the wire.
(b) the current through the wire is increased
(c) the current through the wire is reversed.
Magnetic effect of current was discovered by ______.
What do you mean by the magnetic effect?
A student was asked to perform an experiment to study the force on a current carrying conductor in a magnetic field. He took a small aluminium rod AB, a strong horse shoe magnet, some connecting wires, a battery and a switch and connected them as shown. He observed that on passing current, the rod gets displaced. On reversing the direction of current, the direction of displacement also gets reversed. On the basis of your understanding of this phenomenon, answer the following questions:
- Why does the rod get displaced on passing current through it?
- State the rule that determines the direction of the force on the conductor AB.
-
- If the U-shaped magnet is held vertically and the aluminium rod is suspended horizontally with its end B towards due north, then on passing current through the rod from B to A as shown, in which direction will the rod be displaced?
- Name any two devices that use current carrying conductors and magnetic fields.
OR
Draw the pattern of magnetic field lines produced around a current carrying straight conductor held vertically on a horizontal cardboard. Indicate the direction of the field lines as well as the direction of current flowing through the conductor.
