Magnetism Chapter 9 PDF

Magnetism Chapter 9  Table of contents 01 02 03 Magnetic field Earth’s Electromagnet magnetic field 01 Magnetic field Even the tiniest bolt must be screwed on tightly in order to perform its best. —Jing S...

Magnetism Chapter 9  Table of contents 01 02 03 Magnetic field Earth’s Electromagnet magnetic field 01 Magnetic field Even the tiniest bolt must be screwed on tightly in order to perform its best. —Jing Si Aphorism  Learning outcomes: 9.1.1 Describe what is meant by the term magnetic field. 9.1.2 Explain how to detect a magnetic field. 9.1.3 Draw magnetic field lines around a magnet and between two magnets according to the directions and its strength. Magnets Most materials are not magnetic, but some are. A magnetic material can be magnetised or will be attracted to a magnet. These metals are magnetic: iron cobalt Nickel Steel Magnets Bar magnet A bar magnet is a permanent magnet. This means that its magnetism is there all the time and cannot be A bar magnet has two magnetic poles: turned on or off. north pole (or north-seeking pole) south pole (or south-seeking pole) Attract and repel If you bring two bar magnets together, there are two things that can happen, attraction and repulsion. Opposite poles attract. Like poles repel. Opposite poles attract Like poles repel Paper clips are attracted to the magnet if they are placed in the magnetic field of the magnet. Paper clips are not attracted to the magnet if they are not in the magnetic field of the magnet. Magnetic field is the area around a magnet where the effects of the magnet can be detected. 9.1.1 Describe what is meant by the term magnetic field? Magnetic field is the area around a magnet where the effects of the magnet can be detected. You cannot see a magnetic field, but you can observe its effects. Magnetic force is a non-contact force because the magnet and the material do not have to touch each other. 9.1.2 Explain how to detect a magnetic field. You can use a compass or iron filings to detect a magnetic field. Compass Iron filings 9.1.3 Draw magnetic field lines around a magnet and between two magnets according to the directions and its strength. Plotting Magnetic Field Lines GCSE Physics Required Practical.mp4  I see these in magnetic field. 1. Does the magnetic field lines cross with each other?No. North 2. The magnetic field lines point from the ___________ pole to the _________ South pole. 3. Each line of magnetic field is continuous. 4. Are the magnetic field line closer or further away from each other near the poles? Closer. The strength of the magnetic force is the strongest near the poles. 9.1.3 Draw magnetic field lines around a magnet and between two magnets according to the directions and its strength. In the diagram, note that: each field line has an arrowhead on it the field lines come out of the north pole and go into the south pole the field lines are more concentrated at the poles The magnetic field is strongest at the poles, where the field lines are most concentrated. Field lines also show what happens to the magnetic fields of two magnets during attraction or repulsion. Field lines lead from one magnet to the other when the magnets attract each other Field lines also show what happens to the magnetic fields of two magnets during attraction or repulsion. Field lines do not lead from one magnet to the other when the magnets repel each other  Uses of magnets Make a tight seal on the Children’s toys. doors to refrigerators and freezers A compass uses a magnet to direct its needle to the north pole A compass comprises: Compass a magnetic needle mounted on a pivot (so it can turn freely) a dial to show the direction The north pole (north-seeking pole) of the compass needle points towards the Earth’s north pole. If the needle points to the N on the dial, you know that the compass is pointing north. This lets you navigate outdoors using a map.  How to magnetise iron metal? Iron, nickel and cobalt has magnetic properties, but they do not show them all the time. Example: Steel paper clips do not attract or repel each other. To magnetise iron metal: → Rub the North pole from the middle of the metal to the end. With firm pressure, quickly run the magnet across the piece of metal, repeatedly. → Test the magnetism. Inside the magnet Domains → The tiny particles in the magnet materials. → behave like tiny magnets. A Domains are arranged randomly. → The material does not attract other magnetic materials. → does not point North-South. A domain B Domains are arranged in line. → all north poles in one direction, all south poles in opposite direction. → the material is magnetised. → attract other magnetic materials. B  Activity: Complete workbook page 184 – 186  What did we learned? 9.1.1 Describe what is meant by the term magnetic field. 9.1.2 Explain how to detect a magnetic field. 9.1.3 Draw magnetic field lines around a magnet and between two magnets according to the directions and its strength.