Can I Use My Calculator for the Upcoming Physics Exam?

  • Thread starter Thread starter Alt+F4
  • Start date Start date
  • Tags Tags
    Exam
AI Thread Summary
Using a calculator during the physics exam is a common concern among students. The discussion revolves around applying the right-hand rule to determine the direction of forces in magnetic fields, with participants seeking clarification on how to visualize vector directions. Key points include the importance of aligning the thumb with velocity and fingers with the magnetic field to find the force direction. Additionally, confusion arises regarding the relationship between current, magnetic fields, and the resulting forces, emphasizing the need to understand these concepts thoroughly. Mastery of these principles is crucial for success in the exam.
  • #51
Alt+F4 said:
one more,

http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam2/sp06

question 24.

i did this like 20 times in other exams, i don't know why it doesn't work here but

F= ILBSintheta = MG

(X)(.1)(.5) = (9.8)(1)
X = 196Amps, but the answer is 98 Amps what gives?
is this the same idea on how one side isn't really contibuitng?
 
Last edited by a moderator:
Physics news on Phys.org
  • #52
Alt+F4 said:
is this the same idea on how one side isn't really contibuitng?
I thought you had already resolved this one (#24). For this one you only used one side of the loop when you should have used both sides. Both sides contribute to the torque, so only half the current you calculated is needed.
 
Last edited:
  • #53
OlderDan said:
I thought you had already resolved this one (#24). For this one you only used one side of the loop when you should have used both sides. Both sides contribute to the torqe, so only half the current you calculated is needed.
silly me, thanks a lot for your help like seriously. My TA's arent even that helpful
 
  • #54
Alt+F4 said:
Question 16 please :)
http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam2/fa05


So i tried doing it on Calculator but since sin180 = 0 i get 0
hmm all right so i graphed this, Does it matter if calc is in radian or degree?
 
Last edited by a moderator:
  • #55
http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam2/su06

Question 20
Finger Curl with current
B Field points Down

I woulda picked Rotates it so that the right side comes out of the page and the left goes in.
 
Last edited by a moderator:
  • #56
All right last question until Nov 23rd i think

http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam2/fa03

Question 21


So W = 2piF = (2*3.14*580*10^3) = 3.6E6
>and 1 / ( sqrt 1*10^-3 * .06*10^-6) = 1.2909 E5

what am i doing wrong
 
Last edited by a moderator:
  • #57
Alt+F4 said:
All right last question until Nov 23rd i think

http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam2/fa03

Question 21


So W = 2piF = (2*3.14*580*10^3) = 3.6E6
>and 1 / ( sqrt 1*10^-3 * .06*10^-6) = 1.2909 E5

what am i doing wrong
You are supposed to be finding the value of C that will make the resonant frequency of the circuit the desired broadcast frequency. How does C affect the net capacitance of the circuit?
 
Last edited by a moderator:
  • #58
Alt+F4 said:
http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam2/su06

Question 20
Finger Curl with current
B Field points Down

I woulda picked Rotates it so that the right side comes out of the page and the left goes in.
Currents parallel to magnetic fields experience no force. Currents at right angles do.
 
Last edited by a moderator:
  • #59
Alt+F4 said:
hmm all right so i graphed this, Does it matter if calc is in radian or degree?
Yes. Always use radians for these time dependent problems. If they ask for phase in degrees, convert it from radians. If they give phase in degrees, convert it to radians. Angular frequency is always in radians/sec.
 
  • #60
OlderDan said:
Yes. Always use radians for these time dependent problems. If they ask for phase in degrees, convert it from radians. If they give phase in degrees, convert it to radians. Angular frequency is always in radians/sec.
all right but for some reason when i graph in Radian mode i seriously get like -6 and -5 values unless i am doing something wrong with it
 
  • #61
All right i need a CLarifcation on this one
http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam2/sp06

Question 21


The angle i pick should be what to the field line? i wanted to do 90-22.5 but that won't work. Thanks alot
 
Last edited by a moderator:
  • #62
Last Problem then I am off to exam, Thanks Olderdan and whoever else that helped me. Really appreciate it

http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam2/fa05


Question 8
 
Last edited by a moderator:
  • #63
Alt+F4 said:
All right i need a CLarifcation on this one
http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam2/sp06

Question 21


The angle i pick should be what to the field line? i wanted to do 90-22.5 but that won't work. Thanks alot
Rotate through the small angle from the direction of v to the direction of B. It is just 22.5
 
Last edited by a moderator:
  • #64
Alt+F4 said:
Last Problem then I am off to exam, Thanks Olderdan and whoever else that helped me. Really appreciate it

http://online.physics.uiuc.edu/cgi/courses/shell/phys102/fall06/prep2a.pl?practice/exam2/fa05


Question 8
Flux is
Φ = BAcosθ where θ is the angle between the loop normal and B. θ = 30 degrees

The only thing changing is B, so

dΦ/dt = (Acosθ)dB/dt
 
Last edited by a moderator:
  • #65
Can't you take the exam for me?
 
  • #66
Alt+F4 said:
Can't you take the exam for me?
What exam are you taking? Could I bring all my reference materials with me? I still remember how to do this stuff, but it sure is nice having the references readily available when you don't remember the exact formulas, values of constants, etc.
 
  • #67
OlderDan said:
What exam are you taking? Could I bring all my reference materials with me? I still remember how to do this stuff, but it sure is nice having the references readily available when you don't remember the exact formulas, values of constants, etc.
nope no refrence but u could program ur calculator. I am takin physics exam in like 2 hrs.
 
Back
Top