Long answer questions
1. State and explain the properties of magnets in brief
2. How will you test if a given piece of iron is a magnet?
3. Describe a method to make a solenoid. 4. Explain the working of an electric bell.
Answers
Answer:
1.All magnets have two poles: the North Pole and the South Pole
Magnets attract ferromagnetic materials such as iron, nickel, and cobalt.
The magnetic force of a magnet is stronger at its poles than in the middle.
A freely suspended magnet always points in North-South direction.
There are two types of magnet: Permanent and Temporary magnets. Permanent magnets remain magnetized even without the influence of the external magnetic field. While, temporary magnets lose their magnetism when removed from the external magnetic field, such as an iron pin.
2.Bring one pole of a bar magnet ( say the north pole ) close to both the ends of the substance , one by one . If one end is attracted and the other end is repelled , the given substance is a magnet. If both ends are attracted , the given substance is not a magnet.
3.The solenoid simply works on the principle of “electromagnetism”. When the current flow through the coil magnetic field is generated in it, if you place a metal core inside the coil the magnetic lines of flux is concentrated on the core which increases the induction of the coil as compared to the air core
4.A bell works with the principle of working of electromagnetism. When the switch is pushed on, the circuit gets completed and the current starts flowing through the U-shaped electromagnet which creates a magnetic field in the core. This attracts the iron armature.
Explanation:
the magnet has two poles
north pole and south pole .
the magnet get attracted in opposite sides .
it gets repelsion in ťhę same direction .
ťhę magnatic force is very strong .......