# ► GATE 2013, Physics, Question and Answers Comment Here

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GATE 2013 Question and Answers Comment Here, with explanation of answers..

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The isospin and baryon number of a U quark.

ReplyDelete1, 1/3

Deleteprob curr density prob 0.25

Deletethey asked in the inverse lattice no so the bcc is fcc and use reciprocal lattice vector formula to find the magnitude

Deleteif any one remember the data of zeeman effect prob pls post here

Deletepls post question paper

ReplyDelete1/2. 1/3

ReplyDeleteUp quark is isospin doublet so isospin is 1/2 and baryon no. is 1/3.

ReplyDelete1/2

Delete1/3

anjali ahalawat

bcc lattice question,question on superconductor, match about phonon polariton,free energy first transition,four indistinguisable particle on five boxes,same type question on fermion,second order tensor pressure moment of inertia,stress,strain,the problem for some questions dont have any choics you just have to enter the numerical values reduces the arbitrariness and finding answe r by eliminating choices.aptitude seems a bit easy comparing previous papers.

ReplyDeleteIt is correct answer for U quark.

ReplyDeleteya its 1/2 and 1/3

ReplyDeletewt about the no of spectral lines in sodium 2D to 2P transitions...??

ReplyDeleteeight....

Deletehow its 8?, for 2D l=2.s=1/2,for 2p l=1, s=1/2 so j=5/2 and 3/2 for 2D. and j=3/2 and 1/2 for 2p. and now j has 2j+1 values.

Delete5 spectral lines

Deletespin multiplicity is S=2s+1 so calculate for resultant s for no of spectral lines

Delete12

DeleteThis comment has been removed by the author.

Delete12 ???

Deleteno its not 5 not 8 not 12...........ok

Deletethere may be no of transitions corresponds to single spectral line so they asked practically observed spectrl lines among all transitions

Delete2D->2P transitions are diffuse series transition so it has only Triplet so 3 lines alone appears

Delete2D 5/2, 2D 3/2 , 2P 3/2 , 2P 1/2 since the transition from 2D 5/2 to 2P 1/2 is forbidden so no line hence 2D 5/2 to 2P 3/2 , 2D 3/2 to 2P 3/2, 2D 3/2 to 2P 1/2 will give weak , weaker and weakest line respectively.

Delete1)wt was the expectation value of s.j in given magnetic moment?

ReplyDelete2)wt was the expectation value of exp(ia.p)for an ideal gas in MB statistics.

3) wt was the degenerate value of a 3*3 matrix having diagonal element equal to 4 and rest were -1?

the degenerate eigen value is 5 (I got).

Deleteyes it is 5

Deleteyes it is 5

Deleteya it is 1/2,1/3

ReplyDeleterelativistic force solution ?

ReplyDeletewhat about the force and acceleration relation in relativity. My answer could not match any four of them. Later i checked my scratch paper answer on beiser book. it's matched. So guys whats your take on this.

ReplyDelete(C) option

Deletewhat was that c option

Deletecanonical momentum problem..L=alpha.q(dot)square-beta.q square

ReplyDeleteAnswer is p=2.alpha.q(dot)

ya its correct but its not conserved so its not cyclic coordinate

Deletehey any solved the spin matrix problem check it i gt 2.8 check it i think i m sure

ReplyDelete