Day 24 Motional EMF, Maxwell’s Equation and Induction

At the beginning of the class, we did an online activity that has 13 questions about EMF.

In this activity, there is a magnet connected to the current. And there is a copper stick in the middle of the magnet. We predicted that as the current is on, the stick will roll out.

This is a short video shows the result

In this picture, we drew a graph to show what happened in the system for the activity. And if the current is inverse, the force will be inverse also.

Then, we did another 13 online activity problems on motional EMF

The Maxwell's equations were introduced to us!

In this picture, we were deriving the equation of I = C dv/dt by using V = L dI/dt, V = RI, and C = Q/V

Then by the equations of magnetic field and flux, we derived the equation for inductance (L)

Then we did a practice problem on finding inductance.

We were looking the unit of inductance and we got kg*m^2/C^2 which the actual unit is called Henry (H)

Then we begin to learn RC circuit, on the left is the circuit that has an inductor. On the right is the I vs. t graph which represents when t increases, V and I are 0, and then rapidly increase.

In this picture, we find the time constant τ = L/R

Then we did a practice problem based on τ.

Conclusion

Today in class, we learned about EMF induced, Maxwell's equations, motional EMF and inductance. Also, we did some problems that involve inductor and τ.