Which of the following electromagnetic waves have the minimum frequency?

The frequency range from $3 \times 10^9 \, Hz$ to $3 \times 10^{10} \, Hz$ is known as:

Which of the following are not electromagnetic waves?

Which of the following radiations has the least wavelength?

$A$ source of power $4 \ kW$ emits $10^{20}$ photons in $1 \ s$. In which region of the electromagnetic spectrum does the emitted radiation lie?

Electromagnetic waves with wavelengths ranging from $3 \times 10^{-3} \, m$ to $1 \, m$ are used in satellite communication. What is the corresponding frequency range? (Given $c = 3 \times 10^8 \, m/s$)