### Discussion :: Inductors - General Questions (Q.No.19)

Kirthikumar Rao said: (Nov 23, 2011) | |

time constant T=(L/R) to reach max current it will take appr 5T time=5(320u/3.3k) =0.48us |

Feliciano said: (Apr 25, 2012) | |

Time constant for an RL circuit is not R*L! It is instead L/R, which makes Time Constant equal to 5* (320u/3. 3K) = 0.4848. |

Rrgiri said: (Mar 1, 2014) | |

How it s possible ? @Vikas time constant is R/L or R*L ? |

Rajat said: (Mar 4, 2014) | |

What is time constant? |

Ganesh said: (Apr 26, 2014) | |

Time constant for RL circuit is L/R SO time constant = (320*10^(-6)/3.3*10^(3)) time taken to reach final value is approximately 5T = 0.48*10^(-6). |

Ekanath Methre said: (Apr 30, 2015) | |

How did you took 5T? Please explain it. |

Tejas Gouda said: (May 6, 2015) | |

Why we need to multiply it by 5? How the time taken will be approximately 5T? Why can't it be 10T? Time constant means L/R not LR. |

11Kv said: (Jun 12, 2015) | |

Time constant for inductor is L/R. |

Roopesh D M said: (Jun 18, 2015) | |

The time required for the current flowing in the LR series circuit to reach its maximum steady state value is equivalent to about 5 time constants or 5T. This time constant T, is measured by T = L/R, in seconds, were are is the value of the resistor in ohms and L is the value of the inductor in Henries. |

Stuti Kushwaha said: (Feb 15, 2016) | |

Time constant of LR circuit is L/R. So here after multiplying by 5 we get answer is 0.484 micros. |

Shoaib said: (Oct 28, 2016) | |

TIME CONSTANT AND CURRENT RELATIONSHIP: 0 0% of max current. 1Ts 63.2% of max current. 2Ts 86.5% of max current. 3Ts 95% of max current. 4Ts 98.2% of max current. 5Ts 100% of max current. So, first we know that the maximum possible current through the circuit will be full, means the 100% of max current and the time constant will be 5Ts so, Time constant => T= (L/R) = (320u/3.3k). When it reaches max current(100%) it will take 5Ts. So 5Ts = 5(320u/3.3k), =0.48us. |

Dhaval said: (May 4, 2017) | |

Thanks @Shoaib. |

Rehman said: (Dec 5, 2019) | |

Good @Shoaib. |

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