Hi. I started studying LR circuits and the first thing that made me do searches in textbooks of mine and in the internet was the time constant which is surprisingly not L times R, but L/R which would mean the time needed to store and release energy is being prolonged with decreasing the R. And so I managed to explain it to myself and the explanation was this: When you initially close the switch, the current through the inductor would try to rise from 0 to its maximum value, but this changing I would create an expanding magnetic field which would induce counter emf. And so because of that, the current won't immediately reach its maximum value. Instead, every 1time constant this current will rise by 63,2% of the final minus the previous value. When it reaches maximum there is no more expanding magnetic field and the emf disappears. During this time the inductor is "charging". By increasing the resistance, we decrease the value of the maximum current and so the current through the inductor would reach its maximum earlier. This alone would mean that if R increases the time constant decreases. For discharging > since the current through the inductor is now smaller since we increased the resistance, the magnetic field created by it is weaker. And when we turn off the power supply, there will be less emf induced and thereby this emf will disappear quicker.
Did I got it right?

 

hi HG.
This link may help to explain.
Is this sentence is correct.? no more expanding magnetic field. Think radio transmission.
E

http://hades.mech.northwestern.edu/index.php/RC_and_RL_Exponential_Responses