Can someone explain how current/fields are induced when a bar magnet is pushed into a coil of wire? Like how do we know what direction they will be?
A little bit of insight into how magnetic fields can be induced is related to the fact that electric and magnetic fields are actually the same thing. Here's an example of what I mean. You'll need to understand the result that two people moving at a constant velocity with respect to each other in inertial frames (i.e. obeys Newton's first law, so that they're not accelerating) measure the same forces.
Suppose you have two people, A and B. A is 'stationary' and B moves at a constant velocity v with respect to A. Let's suppose there is a proton moving with B, so that B sees the proton as stationary. Suppose A sets up a magnetic field. As the proton is a charged moving particle, it is affected by the magnetic field (assuming it's not moving parallel to the magnetic field) and experiences a force. B must therefore also record a force on the proton, somehow. But according to B, the proton is stationary and we know magnetic fields don't operate on stationary charges. Hence this force must be due to something else, and this something else is an electric field.
I can't definitively answer your question as to how induction comes about, but it'll be something to do with that.
Couple questions:
Describe how the wave-particle duality of electrons can be used to explain the quantised energy levels in atoms.
I may be missing something crucially simple here, but I don't really know how to answer this question.
Which one or more of the following phenomena can be modeled by a pure wave model of light?
A - The Photoelectric Effect
B - Refraction
C - Double - source interference of light
D - Reflection
E - Diffraction
F - The Compton Effect
Maybe I'm just getting caught up on 'pure wave model' for this question, but my i keep reading that reflection and refraction can be modeled by either a wave or particle. So going off that i said the answers were C and E, but apparently the answers are B , C, D ,E. Is that correct?
Refraction can't be modelled by a particle theory. I remember in year twelve seeing a presentation on how Newton's particle theory of light predicts an increase in the speed of light in water as opposed to air, which is clearly false.
The question says what 'CAN' be modelled by a wave model. So anything that is explained by a wave model is a valid answer.