- If switch S' is closed and kept closed, the end of the core that is market W becomes:
I answered "a North pole temporarily." I used the right hand to rule to get North-pole, which is correct in the answers, but got the second part wrong. I stated temporarily, while the answer states permanently. My explanation is that it's temporary because there is not a change in magnetic field once the switch is closed, that would induce a current.
The textbook's explanation is as follows: "The coil on the left becomes an electromagnet. Conventional current goes from plus to minus outside the battery. Grasp the coil with the right hand so that the fingers point in the direction of conventional current; the outstretched thumb points in the direction of the North pole: in this case, W."
Which is correct?
- The instant after switch S' is closed, the conventional current in wire YZ will be from...
I realised that the magnetic field at around YZ is facing in the direction roughly of the vector YZ (as field lines go from North to South). However, I was not able to find a direction of current that would oppose this change in magnetic field.
Could an explanation be offered for both questions?