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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.
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उत्तर
The magnetic effect of a coil can be increased by increasing the number of turnsincreasing the current or inserting an iron core.
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संबंधित प्रश्न
An electric bell has an electromagnet.
The direction of current flowing in the coil of an electromagnet at its two ends X and Y are as shown below:
What is the polarity of end X?
What is the polarity of end Y?
Name and state the rule which you have used to determine the polarities.
When the switch S is closed in the figure given below, the pointer of the galvanometer moves to the right.
If S is kept closed, will the pointer:
(a) return to zero?
(b) stay over on the right?
(c) move to the left and stay there
(d) move to and fro until S is opened
If fuse of 250 mA, 500 mA, 1 A, 5 A and 10 A were available, which one would be the most suitable for protecting an amplifier rated at 240 V, 180 W?
Write the correct option by observing the figures.
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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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.
Identify the given figure, write the labels of it.
Explain the magnetic field created around a straight current carrying conductor with the help of a diagram.
A soft iron bar is introduced inside the current-carrying solenoid. The magnetic field inside the solenoid ____________.
Why do we cover plug pin holes which are within the reach of children with cellotape or a plastic cover when not in use?
How does the magnetic effect of electric current help in the working of an electric bell? Explain with the help of a diagram.
______ are also used to remove splinters of steel or iron in hospitals dealing with eye injuries.
What do you mean by the magnetic effect?
An electric bell contains an ______, consisting of coils of insulated wire wound around
iron rods.
A wire with green insulation is usually the live wire of an electric supply.
Define the magnetic effect of electric current.
The figure given below shows the magnetic field around the conductor. Study it and answer the questions:
- What changes are caused by increasing current?
- What do you see when the magnetic needle is kept a little away from the wire?
- In the second part of the figure, the iron filings arrange themselves in a circular manner around the wire. Why does this happen?
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?
A rectangular loop ABCD carrying a current I is situated near a straight conductor XY, such that the conductor is parallel to the side AB of the loop and is in the plane of the loop. If a steady current I is established in the conductor as shown, the conductor XY will ______.
