Moar ideas to implementations q's! (1 Viewer)

[x.Exhaust.x]

1. What was the importance of Hertz's experiment? (the experiment where he investigates the nature of radio waves).

I understand how he performed the experiment by using parabolic mirrors and primary/secondary loop, but the importance is what I'm currently confused with.

2. Discuss why shortcomings in current technologies lead to an increased knowledge in materials.

I don't understand the shortcoming part.

3. A student is trying to investigate the photoelectric effect. She shines monochromatic light of varying frequences at a sample and measures the energy of the photoelectrons.

Another student says the experiment is all wrong since they varied the intensity in between trails. Discuss this accusation.

4. Discuss how a simple black and white rear projection TV functions.

The simple black and white rear projection TV functions by cathode rays.

Firstly, electrons are ejected from the cathode. Moving the beam is done by deflecting coils, whereby a magnetic field is set up, moving it up and down. The focusing coil is used to ensure the three beams do not interact with one another.And finally, the electrons hit the fluroscent screen at different intensities by 3 beams (RGB).

I talked about colour TV, but not black and white. What are the differences and what changes should I make in my answer?

5. The term superconductivity is one that is commonly misunderstood by the public. Discuss the need for extremely low temperatures in order to allow a Type I superconductor to superconduct.

Superconductivity is a phenomenon whereby a material is able to conduct without any resistance, and excludes all magnetic fields. This will only occur below some critical temperature (Tc).

How would I discuss this question? List the advantages and disadvantages? E.g. Maglev trains creating faster and efficient speeds by magnetic levitation, no friction occurring, MRI imaging, expensive and difficult to maintain at low temperatures etc.

Ty.

 

[youngminii]

Oh come on, we do this at Intuition ==;;
1. Hertz's experiment was so important because he experimentally proved that radio waves (an E.M.R.) followed the laws of Optics (parabolic mirrors and stuff). Which meant that light was simply an E.M.R. allowing the multiple areas of study to be treated as one.

2. Wha? Lol..

3. The accusation is invalid as the energy of the photoelectrons is given by e=hf, which states that intensity has no bearing on the energy. However, if the experiment was trying to find the amount of photoelectrons that bounced off, the accusation would have been valid as the amount of photoelectrons depends on the intensity. Also, the accusation is not unfounded as experimental conditions should remain constant at all times.

4. I DON'T KNOW SHIT ABOUT CATHODE RAYS.

5. Discuss as in, give reasons for and against. Not adv./disadv. in this question..
Type I superconductors require extremely low temperatures (nearing 0K) to superconduct. The BSC theory states that when they are colder than their critical temperatures (near 0K), electrons join together through the help of a phonon (emitted because of the movement of the lattice caused by the electron's charge) to become a cooper pair and travel through the lattice unhindered. This allows the superconductor to superconduct. If it weren't this cold, the lattice would vibrate too much and phonons would be emitted everywhere, not allowing the electrons to join together.

I know why you're confused about Q5. I did what I did because they made specific mention of Type I superconductors, which means they want you to talk about the BSC theory (since it doesn't apply for Type II). Hope I helped.

Btw, I'm fucked for Intuition lol, haven't marked down anything since Week 6 and I haven't done 3 homeworks. Sanj is threatening to disenroll if I don't catch up quick.

Edit: Perhaps for Q2.. (not sure about this)
Shortcomings in current technologies cause people to experiment and research unknown things. People are curious by nature and will strive to discover the unknown. Also, many materials (including superconductors) have been discovered by accident. These unintended mistakes were caused by shortcoming in our current technologies and will lead to the discover of many new things.
=S

 

[k02033]

states that intensity has no bearing on the energy.

thats not true in a general, intensity is a measurment of how much energy the radiation delivers to the cathode per unit of time per unit of area of the cathode. as an equation you can think of intensity as I=nhf, where n is how many photons lands on the cathode per unit of time per unit of area. So there are 2 ways of increasing the radiation intensity, one is to increases its frequency or increase how many photons are emitted, or a combination of both.

but we all know that the kinetic energy of photoelectrons are only dependent on hf, ie the energy of each individual photon.

If i increase teh frequency of the radiation keeping n constant i can indeed increase intensity I=nhf

but this way of increasing intensity can actually increase photoelectron energy, since i am varying f.

so its only safe to say that changing the intensity of EMR while not varying its frequency will not change the photoelectron energy, but increase current

all these assumes f>fo obviously.

 

[x.Exhaust.x]

Btw, I'm fucked for Intuition lol, haven't marked down anything since Week 6 and I haven't done 3 homeworks. Sanj is threatening to disenroll if I don't catch up quick.

And I thought I was fucked. Thanks for the help!