A: The Earth behaves like a giant magnet, which is why freely suspended magnets align themselves in the north-south direction.
Q: What is a lodestone?
A: A lodestone is a naturally occurring magnet discovered in ancient times. It was used by sailors in olden days for navigation.
Q: How can you make an artificial magnet using a bar magnet?
A: You can make an artificial magnet by repeatedly stroking an iron object (like a needle) with a bar magnet in one direction. This process is called magnetization.
Q: What is the matsya-yantra?
A: The matsya-yantra (or machchh-yantra) was an early navigational device used by Indians. It consisted of a magnetized fish-shaped iron piece kept in a vessel of oil, functioning similar to a modern compass.
Q: How can you test if an object is magnetic without using a magnet?
A: Suspend the object freely (like hanging it with a thread). If it’s a magnet, it will align itself in the north-south direction after coming to rest.
Q: Why do magnets attract more iron filings at their ends?
A: The magnetic field is strongest at the poles (ends) of a magnet, so more iron filings are attracted to these areas.
Q: What are some common shapes of artificial magnets?
A: Common shapes include bar magnets, U-shaped magnets, ring magnets, disc magnets, and spherical magnets.
Q: How should magnets be stored to maintain their strength?
A: Magnets should be stored in pairs with unlike poles on the same side, separated by a piece of wood. Two pieces of soft iron should be placed across the ends.
Q: Can magnetic force work through liquids?
A: Yes, magnetic force can work through liquids. For example, a magnet can attract a steel paperclip in water without touching the water.
Q: What is the significance of the red end of a compass needle?
A: The red end of a compass needle typically points towards the North direction.
Q: How does knowing about magnetic and non-magnetic materials help in daily life?
A: This knowledge can be useful in various situations, such as separating materials, designing latches for boxes, or understanding how certain devices work (like electric motors or speakers).