Question

For a parallel plate transmission line, let v be the speed of propagation and Z be the characteristic impedance. Neglecting fringe effects, a reduction of the spacing between the plates by a factor of two results in

(A) halving of v and no change in Z

(B) no change in v and halving of Z

(C) no change in both v and Z

(D) halving of both v and Z 

Answer 1

Correct option (B) no change in v and halving of Z

Explanation:

Z₀ = (276/√∈_r)log(d/r)

d  → distance between the two plates

so, z_o – changes, if the spacing between the plates changes. 

V = 1/√LC → independent of spacing between the plates