Question

A transmitter supplies 9 kW to the aerial when unmodulated. The power radiated when modulated to 40% is

• A. 5 kW
• B. 9.72 kW
• C. 10 kW
• D. 12 kW

Answer 1

The correct option is B 9.72 kW

$P_t$ = $P_c[1+\frac{m^2}{2}]$ = 9 [1 + $\frac{{\left(0.4\right)}^2}{2}$]
= 9 [1 + $\frac{0.16}{2}$] ($\because$ m = 40 % = 0.4)
= 9 (1.08) = 9.72 kW