Ground waves are polarized in which direction?

In amplitude modulation,the amplitude of the carrier wave is $A_c$ and that of the modulating signal is $A_m$. In practice,the ratio of $A_m$ to $A_c$ is kept less than or equal to $1$ to avoid:

Each television channel is allocated a bandwidth of approximately ........?

Assertion $(A)$: Television signals are received through sky-wave propagation.
Reason $(R)$: The ionosphere reflects electromagnetic waves of frequencies in the range $(3-30)$ $MHz$.
Choose the correct option.

$A$ message signal of frequency $3\,kHz$ is used to modulate a carrier signal of frequency $1.5\,MHz$. The bandwidth of the amplitude modulated wave is

The mathematical form of an $AM$ wave is given by $e = 50 (1 + 0.5 \sin(2\pi \times 5 \times 10^{3} t)) \sin(31.4 \times 10^{6} t) \text{ V}$. For the given $AM$ wave,the carrier frequency is ....... and the modulating frequency is .......