My cell phone has an antenna about 10.00cm long. If this is one quarter of the wavelength of the radiation, at what frequency in Megahertz does it operate? Note that cell phones, like radio, transmit sounds via electromagnetic waves which travel at the speed of light or 3x108m/s
V = 3*10^8m/s = 300 m/uS.
L = V / F = 4*10cm = 40cm = 0.4 m. =
Wavelength.
300 / F = 0.4.
0.4F = 300.
F = 300 / 0.4 = 750 Mhz.