Physics Unit 3b experiment predictions??please share

[Mufaddal]

so guys,
which experiment is most likely to be asked? i am thinking plancks constant or young modulus...please give your suggestions

 

[Hamzeh S]

The Graph part im thinking planks constant about the experiment idk

 

[Buzzkiller]

whats a plank constant?

 

[Mufaddal]

whats a plank constant?

it is the relation between energy of a photon and the frequency of its associated electromagnetic wave

 

[jackoo123]

I think there's going to be Newton's second law exp. They still didnt bring in any exam. Not sure though

 

[jackoo123]

Bring it*

 

[Hamzeh S]

guys can someone explain to me the planck's constant experiment ? i dont quite get it

 

[Madness]

I think there's going to be Newton's second law exp. They still didnt bring in any exam. Not sure though

like what ? finding the relation between F and M and A ?

 

[Hamzeh S]

like what ? finding the relation between F and M and A ?

the stopping voltage he says that number of electrons reaching the negative plate will decrease but how ! ? i mean all electrons have the same energy how can ones reach and others dont

 

[aniekan]

I think nothing is coming ______JK

 

[Madness]

I think nothing is coming ______JK

nothing ? blank page lol draw a sketch for ur house

 

[Hamzeh S]

nothing ? blank page lol draw a sketch for ur house

can u plz answer my question ?
the stopping voltage he says that number of electrons reaching the negative plate will decrease but how ! ? i mean all electrons have the same energy how can ones reach and others dont

 

[Madness]

can u plz answer my question ?
the stopping voltage he says that number of electrons reaching the negative plate will decrease but how ! ? i mean all electrons have the same energy how can ones reach and others dont

stopping voltage is the voltage needed to produce enough energy to stop the electrons emitted from the cathode " therefore less electrons will reach the anode which means some of the electrons will reach it but the most of them will stay on the cathode.

 

[Hamzeh S]

stopping voltage is the voltage needed to produce enough energy to stop the electrons emitted from the cathode " therefore less electrons will reach the anode which means some of the electrons will reach it but the most of them will stay on the cathode.

but how each electrons have the same energy as the other one so stopping voltage either stops them all or not

 

[qstar.inc]

exam is tomorrow!!! I just don't know what to study!

 

[jtbteddy]

Same here, I'm so nervous

 

[jtbteddy]

exam is tomorrow!!! I just don't know what to study!

Study these notes, I made them up going through my own notes and a couple of past papers, they're kind of basic, but they're a good starting point!

 

[Manasa]

guys in the paper of jan 2010 ... phys 3b the first question with the microammeter.... why is it C and not D? i didnt understand why to choose the option with x10^-6...???? can someone explain to me why it;s option C?

 

[jtbteddy]

guys in the paper of jan 2010 ... phys 3b the first question with the microammeter.... why is it C and not D? i didnt understand why to choose the option with x10^-6...???? can someone explain to me why it;s option C?

Go over your prefixes,
nano is x 10 -9
micro is x 10 -6
milli is x 10 -3
The scale in that question is in micro, hence why the answer is C

 

[alex]

but how each electrons have the same energy as the other one so stopping voltage either stops them all or not

Actually electrons don't have the same energy. Some may be deeper down and have to do work against the vibrating ions. That's why the einstein equation is: hf = w.f. + KEmax. An electron is said to have maxKe only when it's at the very top and has to do no work against vibrating metal ions.
the potential makes the collecting plate more negative, while the other plate becomes more positive. hence, electrons are repelled when they try to reach the other side, and are attracted back to the positive plate when emitted. Increasing the voltage will make the collecting plate more negative, while the other becomes more positive and less electrons reach the other side/sec. At a certain potential, not even the most energetic electrons(the ones emitted from the top) will reach the other side, that's called the stopping voltage, and there's virtually no current in the circuit.