Tpr cbt 4 ps #8

[MedChallenge]

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Which of the following changes would decrease the sensitivity of the Geiger counter?

A. Using a gas with a higher ionization energy
B. Using a gas with a lower dielectric constant
C. Increasing the radius of the wire
D. Increasing the voltage of the voltage source

Could someone please explain your thought process for this question? A is the correct answer, but why wouldn't B decrease it?

 

[justhanging]

Which of the following changes would decrease the sensitivity of the Geiger counter?

A. Using a gas with a higher ionization energy
B. Using a gas with a lower dielectric constant
C. Increasing the radius of the wire
D. Increasing the voltage of the voltage source

Could someone please explain your thought process for this question? A is the correct answer, but why wouldn't B decrease it?

You got to put some of the passage down for these passage based questions. Geiger counters work through a photocurrent (a current that indirectly results from photon energy). When radiation comes through the Geiger counter, it ionizes the gas in it. The electrons that get ionized create the photocurrent that can then be measured by the geiger counter. A gas with higher ionization energy would need a higher radiation source, so it wont be as sensitive especially to lower energy radiation. Dielectric constants lower the Electric field and since Geiger counters use a cascade effect where one electron knocks off more electrons that eventually go to the anode, the lower electric field will cause less electrons to be knocked off. So using a gas with a HIGH dielectric constant would reduce the sensitivity of the counter.

Where did you get this question? Am really curious.

 

[movax]

Where did you get this question? Am really curious.

I've seen those acronyms in the thread title a lot, I think it means Princeton Review, Computer Based Test #4, Physical Sciences section, question 8.

And like you said, I've got no idea what info is even around in the passage since there's no snippet from it, had to look up how a Geiger counter works on Wiki.

 

[MedChallenge]

You got to put some of the passage down for these passage based questions. Geiger counters work through a photocurrent (a current that indirectly results from photon energy). When radiation comes through the Geiger counter, it ionizes the gas in it. The electrons that get ionized create the photocurrent that can then be measured by the geiger counter. A gas with higher ionization energy would need a higher radiation source, so it wont be as sensitive especially to lower energy radiation. Dielectric constants lower the Electric field and since Geiger counters use a cascade effect where one electron knocks off more electrons that eventually go to the anode, the lower electric field will cause less electrons to be knocked off. So using a gas with a HIGH dielectric constant would reduce the sensitivity of the counter.

Where did you get this question? Am really curious.

I understand that, but I was hoping that someone with TPR could help. TPR doesn't let you copy/paste so it'd be a bit of a pain to type up chunks of the passage that may/may not be relevant. I looked up what a Geiger counter is, too, but I'm still curious to why B couldn't be it.

Dielectric constants lower the Electric field and since Geiger counters use a cascade effect where one electron knocks off more electrons that eventually go to the anode, the lower electric field will cause less electrons to be knocked off.

I feel like you're getting somewhere with that explanation, but can you explain this quoted sentence a bit more possibly using formulas or other concepts?

Yeah, it's The Princeton Review, their 4th test Physical Sciences #8.

If no one has TPR, and I still don't get it, I'll probably stop being lazy 🙂thumbdown, lol) and type up a few parts of the passage.