Advertisements
Advertisements
प्रश्न
State two differences between an electromagnet and a permanent magnet.
Advertisements
उत्तर
| Electromagnet | Permanent magnet |
| It is made up of soft iron | It is made up of steel. |
| The magnetic field strength can be changed. | The magnetic field strength cannot be changed. |
| The electromagnets of very strong field can be made. | The permanent magnets are not so strong. |
संबंधित प्रश्न
Name two factors on which the strength of magnetic field of an electromagnet depends and state how does it depend on the factors stated by you.
What is an electric motor?
Complete the following sentence :
On reserving the direction of current in a wire, the magnetic field produced by it gets _____.
State the condition when an electric charge can give rise to a magnetic field.
What is a permanent magnet? Give one use of it.
State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting and the coil is minimum.
State important properties (or characteristics) of magnetic lines of force around a straight conductor.
A current-carrying solenoid is suspended so as to freely rotate in a horizontal plane. State in what direction will it rest. Give a reason for your answer.
or
When a solenoid that is carrying current is freely suspended, it comes to rest in a particular direction. Why does this happen?
(i) A straight wire conductor passes vertically through a piece of cardboard sprinkled with iron filings. Copy the diagram and show the setting of iron filings when a current is passed through the wire in the upward direction and the cardboard is tapped gently. Draw arrows to represent the direction of the magnetic field lines.
(ii) Name the law which helped you to find the direction of the magnetic field lines.
Which magnet will you use?
Iron is to be separated from trash.
