 Thus , k will have units of impedance , that is , ohms . It is readily apparent that in order for k to be constant , Y must be the dual impedance of Z. A physical interpretation of k can be given by observing that k is the limiting value of Zi as the size of the section ( in terms of values of its components , such as inductances , capacitances , etc . ) approaches zero , while keeping k at its initial value . Thus , k is the characteristic impedance , Z0 , of the transmission line that would be formed by these infinitesimally small sections . It is also the image impedance of the section at resonance , in the case of band @-@ pass filters , or at ω = 0 in the case of low @-@ pass filters . For example , the pictured low @-@ pass half @-@ section has 
 Thus , k will have units of impedance , that is , ohms . It is readily apparent that in order for k to be constant , Y must be the dual impedance of Z. A physical interpretation of k can be given by observing that k is the limiting value of Zi as the size of the section ( in terms of values of its components , such as inductances , capacitances , etc . ) <a href='uninflect' title='1'><mark>approaches</mark></a> zero , while keeping k at its initial value . Thus , k <a href='drop_aux' title='2'><mark>is</mark></a>the characteristic impedance , Z0 , of the transmission line <a href='null_relcl' title='3'><mark>that</mark></a>would be formed by these infinitesimally small sections . It <a href='drop_aux' title='4'><mark>is</mark></a>also the image impedance of the section at resonance , in the case of band @-@ pass filters , or at ω = 0 in the case of low @-@ pass filters . For example , the pictured low @-@ pass half @-@ section <a href='uninflect' title='5'><mark>has</mark></a>
Thus , k will have units of impedance , that is , ohms . It is readily apparent that in order fa k to be constant , Y must be the dual impedance of Z. A physical interpretation of k can be given by observing that k is da limiting value of Zi as the size of the section ( in terms of values of its components , such as inductances , capacitances , etc . ) approach zero , while keeping k at its initial value . Thus , k the characteristic impedance , Z0 , of tdatransmission line would be formed by dese infinitesimally small sections . It also the image impedance of the section at resonance , in the case of band @-@ pass filters , or at ω = 0 in thdaase of low @-@ pass filters . Ffaexample , thedactured low @-@ pass half @-@ section have