# Confused with questioin (minimum value for total impedance)

Thread Starter

#### metelskiy

Joined Oct 22, 2010
66
In an ac series R, L, C circuit, in which R=2K, L=10mH and C = 1uF, the frequency of the source varies between 100 Hz and 15 kH.
The minimum value for the total impedance in the circuit will be:
a. ...0

b. ...1k

c. ...2k

d. ...3k

e. ...4k

I don't really understand what asked
What I did is i found total impedance @ 100Hz=2165Ω and total impedance @ 15kHz=2630Ω
Can someone light me up what do I need to find? Thanks.

#### t_n_k

Joined Mar 6, 2009
5,455
Presumably the series RLC circuit will achieve series resonance at some frequency within the limits 100-15kHz. At that resonance point the circuit will be purely resistive and the answer is then hopefully fairly obvious.

Check the resonance condition for given L & C first.