Question

A rectangular air filled waveguide has a cross section of 4 cm $\times$ 10cm. The minimum frequency which can propagate in the waveguide is

• A. 2.5 GHz
• B. 1.5 GHz
• C. 3.0 GHz
• D. 2.0 GHz

Answer 1

The correct option is B 1.5 GHz

a = 10 cm

$f_c=\frac{v_c}{2a}$

$v_0=3\times {10}^{10}cm/sec$

$f_c=\frac{3\times {10}^{10}}{2\times 10}=1.5\times {10}^9=1.5GHz$