Question 15:

The Probability is: 1- Prob(find only 1) -Prob(find 2) -.....-Prob(find N)

Im not quite sure about how to calculate the above quantity but it has the form P=1-.... , so when i came up to this problem i chose D , which is correct.

Question 39:

Since log(Gain) is linearly dependent on log(w) , G must be exponentialy dependent on w, and due to the decline of G with w, their relation has the form G=Kexp(-aw), a>0. You are not over! You must calculate a.

G=Kexp(-aw) => log(G)=log(K)-alog(w)=>dlog(G)/dlog(w)=-a

By taking a space of dlog(w) and its corespondive dlog(G) in the linear area, you find that a=2. So the correct answer is E.

Question 40:

In decay experiments the standard deviation is defined as the square root

of counts(or rate of decay). So the correct answer is sqrt(9934)~100 , A.

Question 99:

The energy equation in hydrogenic atoms has the form:

E=-13,6*m'*Z^2/n^2

where m'=m1*m2/(m1+m2) is the "reduced mass"of the system (i am not sure if the term "reduced" is correct) and Z the atomic number.

For the electron - positron pair m'=(1/2)mh , where mh is the reduced mass of electron - proton system in the hydrogen atom,and Z=1. So for the ground state (n=1) the correct answer is B

1/2)*13,6 eV.

Question 100:

The correct answer is B: sqrt(l*D). However you will probably won't have the slightest idea about it , just as i did I when i took this test.

However, i thought that the diameter d should not be either to large or too small. l^2/D , l, l/10 should make a very small diameter for the pinhole, and D^2/l an extremely large one. The only possible answer giving a rational diameter is sqrt(l*D).