I wonder why they can mark self induced E1 like below?
If they mark E1 like below, and use KVL, V1+E1 which is wrong. E1 should have been opposing current I1 as per Lenz law, right?

 

hi lin,
Have you considered the winding direction of the secondary?
The 'dot' winding direction indicator.
Check this video link, it should help.
E

 

hi lin,
Have you considered the winding direction of the secondary?
The 'dot' winding direction indicator.
Check this video link, it should help.
E

so in the picture, I thinjk they mark E1 in a wrong way because E1 must oppose applied V1 as per LEnz law.

 

hi lin,
Have you considered the winding direction of the secondary?
The 'dot' winding direction indicator.
Check this video link, it should help.
E

In the picture, they are wrong about E1, right??

 

I wonder why they can mark self induced E1 like below?
If they mark E1 like below, and use KVL, V1+E1 which is wrong. E1 should have been opposing current I1 as per Lenz law, right?
View attachment 341108

Hello,

E1 is obviously marked wrong, but that's only if we interpret this diagram as in the most general case.

This is just a diagram, and that is not usually what we see in books. We see diagrams with associated text, and here we do not have that associated text. We need more context to make a final judgement on the reason for the unusual polarity.
It could be that they want us to interpret the voltage E1 as being in reverse, or they are showing one particular aspect during a certain time period, but there could be other reasons too which we can't know without seeing the entire problem statement and associated diagrams. We may also need to see previous diagrams and problem statements from the same book to get a feel for the authors style of dissertation.

For example, if E1 was 5 volts they may want us to measure it with the meter leads placed as per those polarity symbols. That would mean we would measure -5 volts not +5 volts.
It could have been for a particular time period also. It could have been on the second half cycle which would be the reverse of what we would see on the first half cycle.
There are many possibilities, but without seeing the text we can only guess.

Books are sometimes wrong, but from what I have seen of this book so far it does not look like they are wrong we just need to see more of the book.