How Does an Inductor Affect Current Change Upon Switch Closure?

[Sho Kano]

I've never heard it in those words before, but yes, I suppose that does sound like a qualitative way to put it.

Yes, that certainly looks correct to me.

thank you :)

 

[lychette]

the current through an inductor may not change instantaneously and to talk about this is misleading!
When the switch is closed the current may be zero but it will be changing at a rate given by e = -L.di/dt so it ios possible to describe the current !

 

[phyzguy]

the current through an inductor may not change instantaneously and to talk about this is misleading!
When the switch is closed the current may be zero but it will be changing at a rate given by e = -L.di/dt so it ios possible to describe the current !

I think this is what we have all been saying. The current is zero immediately after the switch is closed, but dI/dt is not zero. What is your point?

 

[lychette]

just making the point that seems to have been lost searching for 'qualitative' explanations...inductor is 'holding back' the battery emf does not sound like a physics explanation. This aftert 49 posts!

 

[Sho Kano]

it

just making the point that seems to have been lost searching for 'qualitative' explanations...inductor is 'holding back' the battery emf does not sound like a physics explanation. This aftert 49 posts!

Please explain n a physics explanation then :)

 

[lychette]

An inductor is a device that produces an 'induced emf' whenever it experiences a changing magnetic fluk linkage.
In this example the changing magnetic flux linkage is caused by a changing current and therefore an induced emf occurs when the current changes.
The induced emf opposes the change in magnetic flux linkage, i.e.opposes the changing current. When the switch is closed the current tends to increase and therefore the induced emf opposes the increasing current i.e opposes the applied emf (I think it is bad to describe this as 'holding back' the battery emf )
When the switch is opened the current tends to decrease and now the induced emf tries to maintain the flow of current i.e it is in the same direction as the battery emf ! Trying to explain this complex problem qualitatively is extremely difficult and confusing.
The explanation is in mathematics.
The induced emf e = -Ldi/dt The minus sign conveys opposition to changing I (magnetic flux) and di/dt conveys the magnitude of the effect