How many kW does a radio use?

Answer 1

There are many different kinds of radios. Here is a sampling:

-- If it runs on batteries and fits in your pocket, it uses something like 0.00009 KW.

-- If it's like a boom-box, runs on batteries and you carry it on your shoulder, then it uses maybe like 0.001 KW.

-- If it plugs into the wall, sits beside your bed, and has a clock and CD player in it, then it uses maybe like 0.005 KW.

-- If it takes up half of a wall in your living room, plays AM, FM, weather alerts and TV audio, and the speakers for it

take up the rest of the wall, then it uses maybe 0.3 KW.

Answer 2

A typical AM radio station may transmit with, let's say, 10,000 watts of power.

That means that the radio waves leaving their transmitting antenna (tower)

carry away 10,000 joules of energy every second.

Answer 3

It's nearly 100% ... in the sense that virtually ALL of the power supplied from the

transmitter to the antenna is radiated outward and transported great distances.

But if you want to CAPTURE substantial amounts of the power and use it elsewhere,

that's where you have a problem, and the overall efficiency really plunges.

Example:

-- A radio transmitter tuned to 1 GHz delivers 100 watts of power to a 15-ft

diameter dish antenna, which focuses the power in a very narrow beam in one

direction.

-- You sit 1 mile away from the transmitter, in exactly the right direction, with

another 15-ft diameter dish pointed directly at the transmitting one, ready to

grab as much of that power as possible when it sails by.

-- With these numbers, your dish succeeds in collecting 0.0348 watt of power.

Relative to the power output of the transmitter, the efficiency realized at the

output of your dish is 0.0348 percent.

(Trust me. I make my living doing this stuff. The math and physics are bullet-proof.)

Answer 4

A clock radio uses about 20 kWh/year on average.

Answer 5

As much as needed:D:D:D:D:D