A transmitter radiates power of 20 kW and its base current

A transmitter radiates power of 20 kW and its base current is 18 A. The radiation resistance of the antenna is—

Power radiated = 20 kW = 20 × 10³ W and we have basic relation of antenna that is I² R_r = Power radiated

R_r =		W	=	20 × 10³	= 61.6 Ω
		l²		18 × 8