Physics Hertz Experiment - Help!? (1 Viewer)

[chickenmicken]

Hi guys, this is my first time posting on bored of studies, so if this is in the wrong section or if i am breaking an rules please let me know

Anyway my predicament:

Our 11 physics class has been given assignment where we design a practical experiment. I have decided to complete a hertz experiment where he transmitted demonstrate the production and transmission of radio waves, and found the speed of light. Apparently this is a year 12 experiment so i am a little bit confused about some of the physics/ circuitry behind the experiment. So just a few questions (just so you guys know i couldn't find much information to answer the following questions that wasn't completing beyond my current scope of knowledge) :

-Does the induction coil or 'spark gap' have anything to do with the frequency/wavelength of the experiment
-If can we measure the 'spark gap' or induction coil to calculate frequency/wavelength.

-What does the transistor radio and static have to do with the experiment? Are we using the static produced by the radio wave to measure frequency? What does changing the frequency of the transistor radio do?

-If none of these how do we measure the wavelength/frequency of the radio wave produced (using high school equipment and formula)

- When completing this experiment should i be proving that radio waves (E.M waves) travel at the speed of light, or how frequency (or period) of the wave affects its wavelength?


Thanks for any information guys, i really appreciate any help you can give me

 

[porcupinetree]

Hi guys, this is my first time posting on bored of studies, so if this is in the wrong section or if i am breaking an rules please let me know

Anyway my predicament:

Our 11 physics class has been given assignment where we design a practical experiment. I have decided to complete a hertz experiment where he transmitted demonstrate the production and transmission of radio waves, and found the speed of light. Apparently this is a year 12 experiment so i am a little bit confused about some of the physics/ circuitry behind the experiment. So just a few questions (just so you guys know i couldn't find much information to answer the following questions that wasn't completing beyond my current scope of knowledge) :

-Does the induction coil or 'spark gap' have anything to do with the frequency/wavelength of the experiment
-If can we measure the 'spark gap' or induction coil to calculate frequency/wavelength.

-What does the transistor radio and static have to do with the experiment? Are we using the static produced by the radio wave to measure frequency? What does changing the frequency of the transistor radio do?

-If none of these how do we measure the wavelength/frequency of the radio wave produced (using high school equipment and formula)

- When completing this experiment should i be proving that radio waves (E.M waves) travel at the speed of light, or how frequency (or period) of the wave affects its wavelength?


Thanks for any information guys, i really appreciate any help you can give me

Here's how the experiment works:

We start with the formula v=fλ. We want to prove that v = c = 3 x 10^8 ms^-1; we do this by finding f and λ and finding their product. f is determined by the induction coil; the induction coil will produce an AC current of a specific frequency which corresponds to the frequency of the resulting radio wave. (Hence, f doesn't need to be experimentally found; f is the same as the frequency of the AC electricity produced by the induction coil.)
Now, we need to somehow find λ. Here's how Hertz did it: He reflected the radio wave(s) in order to create a standing wave (due to constructive and destructive interference), and used his detecting/receiving loop to determine the distance between the antinodes (by examining the intensity of the spark generated in the spark gap of the detecting loop). Hence, he could calculate the wavelength, λ, of the radio waves.
Once f and λ have been found, we have enough information to calculate v (using v=fλ), which should be equal to 3 x 10^8 ms^-1 (if no experimental errors affected our values of f and λ).

 

[Speed6]

Test

 

[chickenmicken]

Thanks for the answer porcupinetree, didn't know that the AC currents frequency was related directly to the experiment, but how would i find the frequency of the AC current? Would i use a multimeter or is there some kind of formula?

Also is there any other way to measure the wavelength of the radio wave? My teacher explained a different way of measuring the wavelength using a transistor radio and possibly static produced by the radio wave?

If not, would i just reflect the radio waves off of aluminum foil, at random distance and angles until they produce a standing wave, or is there a more scientific way? Also how did he know when a standing wave was produced, and how did he use this to determine the wavelength specifically? Did he just measure the distance between the spark gaps?

Also how would i change the frequency of the radio wave, does increasing the gap between the induction 'coils' increase the frequency?

 

[leehuan]

Thanks for the answer porcupinetree, didn't know that the AC currents frequency was related directly to the experiment, but how would i find the frequency of the AC current? Would i use a multimeter or is there some kind of formula?

Also is there any other way to measure the wavelength of the radio wave? My teacher explained a different way of measuring the wavelength using a transistor radio and possibly static produced by the radio wave?

If not, would i just reflect the radio waves off of aluminum foil, at random distance and angles until they produce a standing wave, or is there a more scientific way? Also how did he know when a standing wave was produced, and how did he use this to determine the wavelength specifically? Did he just measure the distance between the spark gaps?

Also how would i change the frequency of the radio wave, does increasing the gap between the induction 'coils' increase the frequency?

We can use a radio to replicate the experiment. HERTZ, however, used the loop.

Spark gap - Antinodes meant the spark gap could be longer (suggesting higher intensity). Nodes meant spark gap virtually didn't exist (suggesting lower intensity).
__________

Frequency of the AC current is preset.
__________

He knew it was produced as if you didn't have a wave, how would you be able to use reflection and interference?

I have forgotten about the last one though. Need someone else to explain something there

 

[chickenmicken]

So could i use a transistor radio to to measure the wavelength of the radio wave without reflecting the wave? I can't use hertz method as i have to design an experiment and use different equipment. If i used the same method as hertz i think it would be counted as copying.

 

[chickenmicken]

Anyone?
Does anyone know?

 

[chickenmicken]

Thanks for all the help guys

Really appreciate it (i'm not trying to be sarcastic)