Question

The basic width of a VHF airway based on 2 VOR's is ________ either side of centreline?

a) 4.0 NM
b) 4.34 NM
c) 8.0 NM
d) 8.68 NM

Answer 1

To find the frequencies of the TV channels, double the lengths of the VHF antenna wires to get the wavelength, and then use the formula f = c / λ. The frequencies are approximately 77.32 MHz and 199.21 MHz for the 1.94 m and 0.753 m wires, respectively, which are within the VHF range of frequencies.

Step-by-step explanation:

To calculate the frequencies for the TV channels based on the lengths of the VHF antenna cross wires, we need to use the relationship between the frequency (f), the wavelength (λ), and the speed of light (c). The formula is f = c / λ. Since the ideal length of the cross wire is half the wavelength, we double the length of the wire to find the wavelength.

For the wire measuring 1.94 meters, the wavelength is 3.88 meters, and the frequency is:

f = c / λ = (3 x 10^8 m/s) / 3.88 m ≈ 77.32 MHz

For the wire measuring 0.753 meters, the wavelength is 1.506 meters, and the frequency is:

f = c / λ = (3 x 10^8 m/s) / 1.506 m ≈ 199.21 MHz

Both these frequencies fall within the VHF range, which is between 54 to 88 MHz for channels 2 through 6, and 174 to 216 MHz for channels 7 through 13.