Introducing
Your new presentation assistant.
Refine, enhance, and tailor your content, source relevant images, and edit visuals quicker than ever before.
Trending searches
Electromagnetism
55
Electromagnetism
Experiment of Hans Christian Oersted- He found a link between electricity and magnetism
Oersted
Any current carrying conductor creates a magnetic field
Deflection of the needle
Direction
Needle deflects only when current passes, so current carrying conductor has magnetic field
Direction
Reverse
Experiment and right hand thumb rule
Rule
1. They are in circles around the wire
2. More current more strength of field
3. Direction is reversed, the deflection of compass needle is also reversed
Properties
4. Magnetic field at any point is the combined effect of earths field and current
Magnetic field in a circular coil
Loops
Properties
1.Near the wires the magnetic field are circular
2. Near the centre the field lines are parallel, uniform
3. More current more strength of magnetic field
Properties
4. More turns more strength
5. Loop acts like dipole and behaves like magnetic disc of same radius
6.At the centre ,field lines are along the axis of loop and normal to its plane
Clock rule
Solenoid
What is a solenoid?
Solenoid
A solenoid is a long piece of wire which is wound in the shape of a coil. When the electric current passes through the coil it creates a relatively uniform magnetic field inside the coil.
Rule for determining north and south poles
Rule
Identify the poles
B
A
B
More examples
Properties
- Magnetic field lines inside solenoid are straight and parallel to the axis of solenoid
- more current magnetic field lines are denser
- more turns more field lines
- soft iron core increases field strength
Properties
Similarity and Dissimilarity
Similarity
Properties
Bar magnet
Solenoid
Magnetic lines
From north to south
Same from north to south
North south
North south
Suspended freely
Yes
Attractive property
Yes
Between magnet and solenoid
Dissimilarity
Strength can be increased for solenoid not for magnet
Polarity can be reversed for solenoid
Electromagnets
I shaped electromagnets
U shaped electromagnets
Electromagnets
More current
More turns
Increasing the strength
Differences
Permanent
Electromagnet
Steel
Made of iron
Difference between electro and permanent magnet
Cannot be increased
Strength can be increased
Cannot be
Demagnetized
Cannot reverse
Reverse the polarity
Uses
Current carrying conductor placed under the influence of external field
https://flexbooks.ck12.org/cbook/cbse-physics-class-10/section/4.6/primary/lesson/force-on-a-current-carrying-conductor-in-a-magnetic-field/
Force on a conductor
Fleming's left hand rule
Fore finger- field
Central finger- current
ThuMb- motion
Identify the direction of motion
S
N
Examples
S
N
Identify the direction of motion
S
N
Changing magnetic field
S
N
Factors affecting thrust
Current
Magnetic field strength
Factors affecting force
Length of the conductor
Principle
Current carrying conductor placed in a magnetic field experiences a force
Parts
DC Motor
Coil
Magnet
Commutator
Brushes
Electromagnetic induction
Electromagnetic Induction or Induction is a process in which a conductor is put in a particular position and magnetic field keeps varying or magnetic field is stationary and a conductor is moving. This produces a Voltage or EMF (Electromotive Force) across the electrical conductor.
Electromagnetic induction
https://phet.colorado.edu/sims/cheerpj/faraday/latest/faraday.html?simulation=faraday
Faraday's law
Faraday's second law of electromagnetic induction states that, the magnitude of induced emf is equal to the rate of change of flux linkages with the coil. The flux linkages is the product of number of turns and the flux
Faraday's law
Lenz law
Lenz's law of electromagnetic induction states that, when an emf is induced according to Faraday's law, the polarity (direction) of that induced emf is such that it opposes the cause of its production.
Lenz law
Fleming's right hand rule
Fleming’s Right - hand Rule
This rule states that if we stretch the thumb, middle finger, and an index
finger in such a way that they are mutually perpendicular to each other.
Such that:
1. Thumb: It is along the direction of motion of the conductor.
2. Middle Finger: It points in the direction of the induced current.
3. Index Finger: It points in the direction of the magnetic field.