IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: THEIGBOY on May 10, 2011, 10:07:13 am

Title: Definitions we need to know for physics A2
Post by: THEIGBOY on May 10, 2011, 10:07:13 am

Guys, I was looking through the syllabus, I couldn't perfectly define the following words/terms -
Magnetic flux density - is it - the amount of flux moving through a particular area - ???
Tesla - It is the unit of Magnetic flux/It is the force (1N) exerted by 1 m of a conductor, through which a current of 1 A is flowing through.
Magnetic Flux - It is the amount of field lines going through a unit area
Weber - ????
Magnetic flux linkage -???
Activity - ???
Decay Constant - ???
Half-life - The amount of time taken to reduce the initial number of molecules to half it's original value during a radioactive decay.
Radian - ratio of arc to radius
Are these definitions ok? and can someone answer the ones that i didn't define :D

Also can someone give the clear difference between magnetic flux density, linkage and just magnetic flux and their respective formulas.
Thank you guys so much :D

Title: Re: Definitions we need to know for physics A2
Post by: yasser37 on May 10, 2011, 10:12:46 am

Tesla: The unit of magnetic flux density where a wire carrying 1 A of current experiences 1 N of force
Decay Constant: probability of decay per unit time
Radian: angle subtended at the center of the circle where the arc is equal in length to the radius
 

Title: Re: Definitions we need to know for physics A2
Post by: THEIGBOY on May 10, 2011, 10:22:47 am

@yasser37,
Thanks for those definitions,
by the way wouldn't Tesla include the length of the conductor as well?, i.e. 1 m of wire carrying 1 A of current experiences a 1 N force,
or  .... (i got this from thefreedictionary.com) "The unit of magnetic flux density in the International System of Units, equal to the magnitude of the magnetic field vector necessary to produce a force of one newton on a charge of one coulomb moving perpendicular to the direction of the magnetic field vector with a velocity of one meter per second. It is equivalent to one weber per square meter"

Title: Re: Definitions we need to know for physics A2
Post by: Sue T on May 10, 2011, 10:36:09 am

here

Title: Re: Definitions we need to know for physics A2
Post by: yasser37 on May 10, 2011, 10:37:17 am

Tesla: The unit of magnetic flux density where a wire carrying 1 A of current experiences 1 N of force per meter.

sorry forgot to mention that


I memorized this definition form marking scheme in june 09 question 6 ;) so it's probably the right one
hope that it helps :)

Title: Re: Definitions we need to know for physics A2
Post by: THEIGBOY on May 10, 2011, 10:44:09 am

@Sue T
wohoooo!!!!!
Amazing notes!!!
Thank you sooo much

@yasser37
Thank you so much for the reference :D... no need to say sorry bro :D....we all make mistakes... (better here than in the real deal...eh? :P)