Magnetic Field, Inductance, RL-Circuit(0519)

Magnetic Field, Inductance, RL-Circuit

Predict the direction when the current through the bar.

We explained the simple mechanism of the rail gun by applying the right hand rule.

Formula derivation for the rail gun. Since the area is changing with time, we write it as A(t)= A_0+ vLt with v is velocity and L is the length of the bar. Since emf depends rate of change of flux  and rate of change of flux depends on rate of change of A. emf has to depend on velocity

Here we kept doing the activity online. Since dA/dt= vL, We have emf=vBL.

L here is inductance= V/ (dI/dt). We know that C=Q/V. We can I= C* (dV/dt). By following the derivation we did on the board, we have L=- N^2*miu_not*A/l

SI unit of Inductance is Henry (H)=  km*m^2/C^2

Here we have current as horizontal graph. The voltage has an exponential curve.

Here we derived formula for tau from L and R. Recall that I=I_0 (1-e^-t/RC) to get tau=L/R.