If a radio receiver amplifies all frequency signals equally and well,it is said to have high . . . . . . .

In frequency modulation,........

Statement-$1$: Sky wave signals are used for long-distance radio communication.
Statement-$2$: These signals are generally less stable than ground wave signals.

For transmission of e.m. wave of audible frequency,these waves are superimposed with waves of

$A$ signal of $0.1 \, kW$ is transmitted in a cable. The attenuation of the cable is $-5 \, dB$ per $km$ and the cable length is $20 \, km$. The power received at the receiver is $10^{-x} \, W$. The value of $x$ is ....... .
$[\text{Gain in } dB = 10 \log_{10}(\frac{P_0}{P_i})]$

The characteristic impedance of a coaxial cable is typically in the range of ..........