what is the time constant of rl circuit
RL circuit These equations show that a series RL circuit has a time constant, usually denoted τ = L/R being the time it takes the voltage across the component to either fall (across the inductor) or rise (across the resistor) to within 1/e of its final value. That is, τ is the time it takes VL to reach V(1/e) and VR to reach V(1 − 1/e).
Planck constant In applications where it is natural to use the angular frequency (i.e. where the frequency is expressed in terms of radians per second instead of cycles per second or hertz) it is often useful to absorb a factor of 2π into the Planck constant. The resulting constant is called the reduced Planck constant. It is equal to the Planck constant divided by 2π, and is denoted ħ (pronounced "h-bar"):