PPT: Electricity: Magnetic and Heating Effects | Science Curiosity Class 8 - New NCERT PDF Download

 Page 1


Electricity: Magnetic
and Heating Effects
Page 2


Electricity: Magnetic
and Heating Effects
Electricity: Magnetic and
Heating Effects
When electric current flows through a conductor, it produces
two important effects:
Magnetic Effect
Current flowing through a wire creates a magnetic field
around it, causing a compass needle to deflect.
Heating Effect
Current flowing through a conductor generates heat due
to resistance, which is used in many household
appliances.
Page 3


Electricity: Magnetic
and Heating Effects
Electricity: Magnetic and
Heating Effects
When electric current flows through a conductor, it produces
two important effects:
Magnetic Effect
Current flowing through a wire creates a magnetic field
around it, causing a compass needle to deflect.
Heating Effect
Current flowing through a conductor generates heat due
to resistance, which is used in many household
appliances.
Does an Electric Current Have a Magnetic Effect?
When electric current flows through a wire, it produces a
magnetic field around it. This is called the magnetic effect
of electric current.
This effect was discovered by Hans Christian Oersted in
1820, who noticed that a compass needle deflected when
placed near a current-carrying wire.
The magnetic field disappears when the current stops
flowing.
The region around a current-carrying wire where its
magnetic effect can be felt is said to have a magnetic
field.
Page 4


Electricity: Magnetic
and Heating Effects
Electricity: Magnetic and
Heating Effects
When electric current flows through a conductor, it produces
two important effects:
Magnetic Effect
Current flowing through a wire creates a magnetic field
around it, causing a compass needle to deflect.
Heating Effect
Current flowing through a conductor generates heat due
to resistance, which is used in many household
appliances.
Does an Electric Current Have a Magnetic Effect?
When electric current flows through a wire, it produces a
magnetic field around it. This is called the magnetic effect
of electric current.
This effect was discovered by Hans Christian Oersted in
1820, who noticed that a compass needle deflected when
placed near a current-carrying wire.
The magnetic field disappears when the current stops
flowing.
The region around a current-carrying wire where its
magnetic effect can be felt is said to have a magnetic
field.
E l e c t r o m a g n e t s
An e l e c t r o m a g n e t is a current-carrying coil that
behaves as a magnet. When current flows through the
coil, it creates a magnetic field.
Adding an iron core makes the electromagnet stronger
Like permanent magnets, electromagnets have two poles
(North and South)
The magnetic effect disappears when current stops flowing
The strength of an electromagnet can be increased by:
Increasing the current
Increasing the number of turns in the coil
Page 5


Electricity: Magnetic
and Heating Effects
Electricity: Magnetic and
Heating Effects
When electric current flows through a conductor, it produces
two important effects:
Magnetic Effect
Current flowing through a wire creates a magnetic field
around it, causing a compass needle to deflect.
Heating Effect
Current flowing through a conductor generates heat due
to resistance, which is used in many household
appliances.
Does an Electric Current Have a Magnetic Effect?
When electric current flows through a wire, it produces a
magnetic field around it. This is called the magnetic effect
of electric current.
This effect was discovered by Hans Christian Oersted in
1820, who noticed that a compass needle deflected when
placed near a current-carrying wire.
The magnetic field disappears when the current stops
flowing.
The region around a current-carrying wire where its
magnetic effect can be felt is said to have a magnetic
field.
E l e c t r o m a g n e t s
An e l e c t r o m a g n e t is a current-carrying coil that
behaves as a magnet. When current flows through the
coil, it creates a magnetic field.
Adding an iron core makes the electromagnet stronger
Like permanent magnets, electromagnets have two poles
(North and South)
The magnetic effect disappears when current stops flowing
The strength of an electromagnet can be increased by:
Increasing the current
Increasing the number of turns in the coil
Lifting Electromagnets
Lifting electromagnets are strong electromagnets used in
industries to lift heavy metal objects.
How they work:
When current is switched ON, the electromagnet creates a
strong magnetic field
This allows it to lift iron/steel objects
When current is switched OFF, the magnetic field
disappears, and objects are released
They are widely used in factories and scrap yards to move, lift,
and sort heavy metal items efficiently.