Give reason for each of the following
**1. Some materials are called magnetic materials.
Because they are attracted to the magnet.
2. Some materials are called non-magnetic materials
Because they are not attracted to the magnet.
*3. The magnet attracts nickel, but doesn’t attract aluminium.
Because nickel is a magnetic material, while aluminium is a non-magnetic material.
4. Aluminium, copper and glass are considered non-magnetic materials.
Because they are not attracted to the magnet.
*5. Iron, cobalt and nickel are magnetic materials.
Because they are attracted to the magnet.
6. One of the poles of the magnet is called north pole and the other is called south pole.
Because it always points to the north pole of the Earth, but the other points to the south pole of the Earth.
*7.The north pole of the magnet attracts the south pole of another magnet, but repels the north pole.
Because the like (similar) magnetic poles repel each other, while the unlike (different) magnetic poles attract each other.
8-When you sprinkle iron filings on a glass plate placed on a magnet, then knock on the glass, the iron filings assembled at the two ends.
Because the magnetic force of the magnet is concentrated at its two poles.
*9-The compass is used to locate the main four directions.
Because its north pole refersيشير to the north direction of the Earth and its south pole refers to the south direction of the Earth.
10. When an electric current flows through a wire winding around a wrought iron nail, the nail attracts iron filings.
Because the electric current changes wrought iron nail into a temporary magnet that is called an electromagnet.
11-When an electric current flows through a wire that is put beside a compass, the compass needle deflects.
Because the electric current has a magnetic effect, where it generates a magnetic field.
12-We must increase the number of coil turns in the electromagnet. In the electromagnet, we must increase the number of batteries.
To increase the magnetic force of the electromagnet.
13-The lifted steel blocks by electromagnet fall down by cutting the electric current that flows through the coil of the electromagnet.
Because by cutting the electric current, the electromagnet loses its magnetic force
14- The presence of a battery in the electromagnet is important.
. Because the battery is a source of the electric current.
*15-We must increase the number of coil turns and the number of batteries in the electromagnet.
To increase the magnetic force of the electromagnet
*16-The electromagnet is very important.
Because it is used in factories to lift the heavy iron or steel blocks and it is used in making many appliances as electric bell, electric mixer, disc drive and TV
*17-The magnet which is made by electricity is called electromagnet
. Because it changes the electric energy into magnetic energy.
18-The small cylinder in the bicycle’s dynamo touches the bicycle’s wheel tire.
. Because by moving the bicycle’s tire, the cylinder moves and the magnet that connect with cylinder moves, so the electric current is generated in the coil causing lightening of the lamp
19-The pointer of the ammeter deflects when moving the copper wire between the two poles of a magnet.
Due to passing the electric current in the copper wire.
20-The deflection of ammeter’s pointer increases by increasing the motion of coil between two poles of a magnet.
Due to generation of more electric current in the copper wire.
21. The huge electric generator is used in electric power stations.
To generate large amount of electricity used for lightening cities and operating factories.
**22. Dynamo changes the mechanical energy into electric energy.
Because by moving the magnet in the coil an electric current is produced ينتج .
**1. Some materials are called magnetic materials.
Because they are attracted to the magnet.
2. Some materials are called non-magnetic materials
Because they are not attracted to the magnet.
*3. The magnet attracts nickel, but doesn’t attract aluminium.
Because nickel is a magnetic material, while aluminium is a non-magnetic material.
4. Aluminium, copper and glass are considered non-magnetic materials.
Because they are not attracted to the magnet.
*5. Iron, cobalt and nickel are magnetic materials.
Because they are attracted to the magnet.
6. One of the poles of the magnet is called north pole and the other is called south pole.
Because it always points to the north pole of the Earth, but the other points to the south pole of the Earth.
*7.The north pole of the magnet attracts the south pole of another magnet, but repels the north pole.
Because the like (similar) magnetic poles repel each other, while the unlike (different) magnetic poles attract each other.
8-When you sprinkle iron filings on a glass plate placed on a magnet, then knock on the glass, the iron filings assembled at the two ends.
Because the magnetic force of the magnet is concentrated at its two poles.
*9-The compass is used to locate the main four directions.
Because its north pole refersيشير to the north direction of the Earth and its south pole refers to the south direction of the Earth.
10. When an electric current flows through a wire winding around a wrought iron nail, the nail attracts iron filings.
Because the electric current changes wrought iron nail into a temporary magnet that is called an electromagnet.
11-When an electric current flows through a wire that is put beside a compass, the compass needle deflects.
Because the electric current has a magnetic effect, where it generates a magnetic field.
12-We must increase the number of coil turns in the electromagnet. In the electromagnet, we must increase the number of batteries.
To increase the magnetic force of the electromagnet.
13-The lifted steel blocks by electromagnet fall down by cutting the electric current that flows through the coil of the electromagnet.
Because by cutting the electric current, the electromagnet loses its magnetic force
14- The presence of a battery in the electromagnet is important.
. Because the battery is a source of the electric current.
*15-We must increase the number of coil turns and the number of batteries in the electromagnet.
To increase the magnetic force of the electromagnet
*16-The electromagnet is very important.
Because it is used in factories to lift the heavy iron or steel blocks and it is used in making many appliances as electric bell, electric mixer, disc drive and TV
*17-The magnet which is made by electricity is called electromagnet
. Because it changes the electric energy into magnetic energy.
18-The small cylinder in the bicycle’s dynamo touches the bicycle’s wheel tire.
. Because by moving the bicycle’s tire, the cylinder moves and the magnet that connect with cylinder moves, so the electric current is generated in the coil causing lightening of the lamp
19-The pointer of the ammeter deflects when moving the copper wire between the two poles of a magnet.
Due to passing the electric current in the copper wire.
20-The deflection of ammeter’s pointer increases by increasing the motion of coil between two poles of a magnet.
Due to generation of more electric current in the copper wire.
21. The huge electric generator is used in electric power stations.
To generate large amount of electricity used for lightening cities and operating factories.
**22. Dynamo changes the mechanical energy into electric energy.
Because by moving the magnet in the coil an electric current is produced ينتج .
