Electro magnetism

Question 1

Pattern of magnetic field in solenoid

Answer 1

Magnetic field inside the solenoid is straight
magnetic field becomes denser if the current increases
Magnetic field increase if the number of turns in the solenoid of given length increase
Magnetic field also increase if the iron rod is placed inside solenoid

Question 2

Similarities between a current carrying solenoid and a bar magnet

Answer 2

Current carrying solenoid behaves like a bar magent
current carrying solenoid sets itself in North South direction when freely suspended
Solenoid also shows attractive property

Question 3

DIssimilarities of solenoid and bar magnet

Answer 3

Strength of magnetic field in solenoid can be changed by changing the current in it
Direction of magnetic field due to the solenoid can be reversed by reversing the direction of current in it

Question 4

How permanent magnet made?

Answer 4

Steel is used instead of soft iron

insulated copper wire is wound across the solenoid

Question 5

Advantages of Electromagnet

Answer 5

Can produce a strong magnetic field
Strength of magnetic field can be changed by changing current
Polarity of electromagnet can be reversed by reversing the direction of solenoid

Question 6

Uses of Electromagnet

Answer 6

In crane
For loading furnace with iron 
For seperating iron pieces from debris
For removing pieces of iron from wound
In several electrical devices 
To study about magnetic field