Only TE10 mode is possible   
 
 Cut-off frequency(in Hz) =   
 
    6.000D+09  
 
 Guide wavelength for TE10 (in cm) =   
 
    4.869206  
 
 TM11 also propagates   
 
 Guide wavelength for TM11 (in cm) =   
 
    4.869206