Time constant in inductors, Physics

Assignment Help:

Time constant in Inductors:

It is impossible to decide exactly when the maximum point is reached on an exponential curve, or when the curve has fallen to exactly zero.   To enable calculations to be performed a  time constant is used. The time constant gives an indication of the time taken for the current to rise to its maximum value or fall to zero. The time constant is defined as either:

  • The time taken for a current to reach its maximum value if the initial rate of increase were maintained.
  • The time taken for the current to reach 0.632 of its maximum value (or 63.2%).

The latter definition arises since it is found that after one time constant, the current has always built up to 63.2% of its maximum value.  The time constant for a series LR circuit is given by:

          Time Constant  = L/R seconds

Therefore, although it is not possible to say exactly when the current reaches its maximum value, for all practical purpose it can be considered a maximum after 5 time constants:

          Maximum Current flows after 5L/R

 

 


Related Discussions:- Time constant in inductors

Radioactive heat transfer, Consider a horizontal cylinder with L/D = large....

Consider a horizontal cylinder with L/D = large. Imagine this cylinder is filled with a liquid to different levels (consider cases where it is 10, 20, 50, 70, 90% full, note that l

Determine the net force, Q. While rummaging in her backpack for her cell p...

Q. While rummaging in her backpack for her cell phone, Sally's Mini-Cooper rear ends Joey's Suburban. Sally's car is totaled while the suburban is fine. If Sally's car hit the sub

Explain linear circuit, Linear circuit :- It can be described as one, wh...

Linear circuit :- It can be described as one, whose parameters are constant i.e. they do not change with voltage or current.

Kinematics, for small values of theta sine theta is equal to tan theta . ho...

for small values of theta sine theta is equal to tan theta . how?

Experiment on thermo electric thermometers, what are some advantages of th...

what are some advantages of the thermo-electric thermometer over the mercury in glass thermometer?

Watt, Watt; W (after J. Watt, 1736-1819): The derived SI unit of power...

Watt; W (after J. Watt, 1736-1819): The derived SI unit of power, explained as a power of 1 J acting onto a period of 1 s; thus it has units of J/s.

Cue ball slip problems, Q. Cue Ball Slip Problems? A cue ball is struck...

Q. Cue Ball Slip Problems? A cue ball is struck beside a line through its centre and parallel to the table. It moves forward primarily with zero angular rotation, sliding acros

Heat transfer, indicate the process of heat exchange that does not depend o...

indicate the process of heat exchange that does not depend on temperature difference between human skin and enviroment a: convection b: evaporation c: radiation d: conduction

Hookes law, Hooke's law (R. Hooke): The stress applied on any solid is...

Hooke's law (R. Hooke): The stress applied on any solid is proportional to the strain it generates in the elastic limit for that solid. The constant of that proportionality is

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd