Physics Unit 4 Exam discussion

[methodsboy]

light and matter Q6

You had to calculate plancks constant and the stopping voltage.

Did anyone get 5E-15 and 1.5?

yep

yep
what about the ave EMF? did u divide that time by 4?

no

hmm.. i had done a similar question to that in a trial and they divided the time by four

[TrueTears]

Wow so much explain questions.

I spammed my cheat sheet

[krzysiek]

I didn't divide the time by four. It gave the time interval for 90 degree turn (which is what you usually take to find EMF)

[crappy]

no, i didnt divide it. although it had average in bolded, I thought I missed something

[avram_grant]

I didn't divide the time by four. It gave the time interval for 90 degree turn (which is what you usually take to find EMF)

yeh thats correct, they didnt give the period of one rotation, so you didnt have to divide by 4

[methodsboy]

no, i didnt divide it. although it had average in bolded, I thought I missed something

Damn! oh well i should get at least 1 or 2 marks for that

[krzysiek]

Yes, the average part got the best of me. I assumed, because it was not a DC generator, but rather an AC generator that it produces a voltage at it's PEAK, hence, the value I got for EMF i thought was a peak value, and we all know average means Voltage / SQRT2   so I applied this to the answer to find the 'average' - I have no idea if that is what they wanted, but for three marks, I do think they wanted something more.

[methodsboy]

Yes, the average part got the best of me. I assumed, because it was not a DC generator, but rather an AC generator that it produces a voltage at it's PEAK, hence, the value I got for EMF i thought was a peak value, and we all know average means Voltage / SQRT2   so I applied this to the answer to find the 'average' - I have no idea if that is what they wanted, but for three marks, I do think they wanted something more.

Hence, my spontaneous decision to divide it by 4...

[ayaz]

hey guys for the question in area of studies 1 core the transformers question it goes correct to 3 decimal places i got 496.
000V was that right or did i make the mistake:(

[TrueTears]

498V 3 sig figs wasn't it?

[naved_s9994]

light and matter Q6

You had to calculate plancks constant and the stopping voltage.

Did anyone get 5E-15 and 1.5?

yep

yep
what about the ave EMF? did u divide that time by 4?

no it already gave it in 90 degrees

[avram_grant]

498V 3 sig figs wasn't it?

yeh thats correct

[moekamo]

exact voltage is when you calculate the instantaneous rate of change of flux with respect to time, and need calculus.
so average is when you use delta flux / delta time over a time period

[TrueTears]

God I spent half the exam just writing the explain questions, wrote so much shit.

[naved_s9994]

Wow so much explain questions.

I spammed my cheat sheet

Id like to take this opportunity to thank you.
Except, I made a heck of ammendments...because of your answers were in written. I converted them
into dot points.