At one time, television sets used "rabbit-ears" antennas. Such an antenna consists of a pair of metal rods. The length of each rod can be adjusted to be one-sixth of a wavelength of an electromagnetic wave whose frequency is 65.0 MHz. How long is each rod?
2007-02-23 04:19:19 · 3 answers · asked by christian m 2 in Science & Mathematics ➔ Physics
Find wavelength = 3 x 10^8 / 65 x 10^6
Divide by 6
2007-02-23 04:24:38 · answer #1 · answered by hello 6 · 0⤊ 0⤋
Which ever teacher wrote this problem is an idiot as far as antenna design goes. A 1/3 wave dipole is a horrible antenna. Look up the speed of light, divide it by 65,000,000 and you'll have the wavelength. It's less that 6 and more than 2 meters just for a sanity check. Then take that number and divide by 6.
2007-02-23 04:24:59 · answer #2 · answered by Gene 7 · 0⤊ 0⤋
Well, 65.0 MHz is 65 Mega-Hertz, or 65 million cycles per second. It travels at the speed of light, of course, being just a different type of electromagnetic radiation, and it goes at very close to 300,000 km per sec. If the frequency was 1 cycle per sec, the wavelength would be 300,000 km.
So what we want is one sixth of one 65 millionth of that distance.
300,000 km divided by 6 is 50,000 km. So far so good.
Now divide that by 65 million, and you get 0.769 m, or about 30 inches.
2007-02-23 04:29:11 · answer #3 · answered by Anonymous · 0⤊ 0⤋