MAGNETISM

Question 1

What are hard and soft materials?

Answer 1

hard =difficult to magnitize but keep their induced magnetism for longer duration

soft = easy to magnetize + loose thier induced megnetism readily

Question 2

what does the term induced magnetism mean?

Answer 2

is the process of inducing magnetism when a magnetic material is attracted + becomes magnetized without having contact with the magnet

Question 3

mention the properties of magnets

Answer 3

1) attract mgnetic materials
2) if manget suspended freely then it will align itself to the north-sith direction
3) one end n pole other end s pole
4) like poles repel and unlike poles attract
5) region around a magnet within which it attracts a material is known as magnetic feild

Question 4

mention 2 magnetic and non magnetic materials

Answer 4

M = steel, iron, cobalt
N.M= brass wood glass

Question 5

what are the features of the magnetic feild prodcued by current passed through a wire

Answer 5

magnetic field is weak
1) magnetic feild lines are in circle
2) Magnetic feilsd stronger whrn it is closer to the wire
3) higher the current stronger the magnetic feild

Question 6

why does the DC motor rectangular coil rotate in an anitclockwise direction?

Answer 6

it is becuase due to the flemings left hand rule it says that on side AB the force acts downwards and on side CD the force acts upwards –> tho these forces are equal in magnitude, they are opposite in direction
THUS MAKE RECTANGULAR COIL ROTATE ANTICLOCKWISE DIRECTION

Question 7

What is the purpose of carbon brushes?

Answer 7

avoid friction btw ring commutators + circuit wires
+ circuit wirers do not tangle with commutators

Question 8

what is the purpose of split ring commutators?

Answer 8

reverses direction of current in the coil
WITH THAT RESULT –> direction of forces also reversed and the coil continous to rotate in same direction