Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
- If the current through the wire is increased, the intensity of the magnetic field also increases.
- It starts deflecting less when the magnetic needle is kept away from the wire.
- The iron fillings get magnetised and arrange themselves in a circular manner around the wire.
APPEARS IN
संबंधित प्रश्न
An electromagnet does not attract a piece of iron.
What is Maxwell's corkscrew rule? For what purpose is if used?
Which way does the wire in the diagram below tend to move?
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 The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly.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 ______.
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?
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?
|
(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.
A soft iron bar is introduced inside the current-carrying solenoid. The magnetic field inside the solenoid ____________.
A uniform magnetic field exists in the plane of paper pointing from left to right as shown in Figure. In the field an electron and a proton move as shown. The electron and the proton experience
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.
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.
Edison used a ______ wire coil is a vacuum glass and discovered the first electric bulb in 1879.
______ cells cannot be recharged after use.
What are MCBs? How do they work?
Define the magnetic effect of electric current.
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?
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.
