# RC & LR time constants

1. Apr 4, 2009

### FrankJ777

How does the relative position(series or parallel) of a resistor affect the calculation of the RC and LC time constants. In other words is a RC time constant still R$$\times$$C requardless of whether or not R and C are parallel or if R and C are in series. Same question with LC time constants, is it $$L/R$$ whether or not L and R are in series or parallel to each other. Thats how it looks in my text book when they derive the time constant, it does seem conterintuitive to me though.

Thanks a lot.

2. Apr 4, 2009

### dlgoff

Last edited by a moderator: Apr 24, 2017