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प्रश्न
Describe some experiment to show that the magnetic field is associated with an electric current.
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उत्तर
We take a thick insulated wire and fix it in north-south direction. Now, we place a plotting compass under the wire. The two ends of the wire are connected to a battery through a switch.
Initially, let us fix the compass needle parallel to the wire, i.e., north-south direction, if no current is flowing through the wire. If we pass a current through the wire by pressing the switch, we observe that the compass needle gets deflected from its north-south position. Again, if current is switched off, the compass needle returns to its original position.
In this experiment, the deflection of compass needle by a current-carrying wire shows that an electric current produces a magnetic field around it. In other words, a magnetic field is associated with an electric current.
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संबंधित प्रश्न
The magnetic effect of current was discovered by:
(a) Maxwell
(b) Fleming
(c) Oersted
(d) Faraday
Name one device which works on the magnetic effect of current.
What device reverses the current?
Which way does the wire in the diagram below tend to move?
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 S-pole is inserted?
(ii) Global warming is a desirable aspect of the intensified greenhouse effect.
Draw magnetic field lines produced around a straight current carrying conductor passing through a cardboard. How will the strength of the magnetic field change when the point where magnetic field is to be determined is moved away from the conductor?
Name any two appliances which works on the phenomenon of magnetic effect of electric current.
A soft iron bar is introduced inside the current-carrying solenoid. The magnetic field inside the solenoid ____________.
If the key in the given arrangement is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane ABCD, the lines are ____________.
What is that instrument which can detect the presence of electric current in a circuit?
In the arrangement shown in Figure there are two coils wound on a non-conducting cylindrical rod. Initially the key is not inserted. Then the key is inserted and later removed. Then
Magnetic effect of current was discovered by ______.
______ are also used to remove splinters of steel or iron in hospitals dealing with eye injuries.
What are MCBs? How do they work?
An electric bell contains an ______, consisting of coils of insulated wire wound around
iron rods.
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.
As shown in the diagram an aluminium rod 'AB' is suspended horizontally between the two poles of a strong horse shoe magnet in such a way that the axis of rod is horizontal and the direction of the magnetic field is vertically upward. The rod is connected in series with a battery and a key.
State giving reason:
- What is observed when a current is passed through the aluminium rod from end B to end A?
- What change is observed in a situation in which the axis of the rod 'AB' is moved and aligned parallel to the magnetic field and current is passed in the rod in the same direction?
