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प्रश्न
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
विकल्प
the deflection in the galvanometer remains zero throughout
there is a momentary deflection in the galvanometer but it dies out shortly and there is no effect when the key is removed
there are momentary galvanometer deflections that die out shortly; the deflections are in the same direction
there are momentary galvanometer deflections that die out shortly; the deflections are in opposite directions
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उत्तर
there are momentary galvanometer deflections that die out shortly; the deflections are in opposite directions
Explanations -
As the current in the first coil changes, the magnetic field associated with it also changes. Thus the magnetic field lines around the other coil also change. Hence the change in magnetic field lines associated with the secondary coil is the cause of induced electric current in it by the process of electromagnetic induction. Due to this reason, a momentary deflection in the galvanometer will be observed which will die out soon when the current flowing through the first coil attains a steady state.
Due to a similar phenomenon, a momentary deflection is again observed in the opposite direction when the key is removed.
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संबंधित प्रश्न
Fill in the following blank with suitable words:
The magnetic effect of a coil can be increased by increasing the number of ........... increasing the ........... or inserting an ........... core.
Name one device which works on the magnetic effect of 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 The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly.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 S-pole is inserted?
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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?
|
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AgCI : White :: CuI2 : ___________
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Draw a neat labelled diagram to show the magnetic effect of electric current.
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A magnetic compass shows a deflection when placed near a current carrying wire. How will the deflection of the compass get affected if the current in the wire is increased? Support your answer with a reason.
Magnetic effect of current was discovered by ______.
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HTRCO
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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?
