Vay chgn dap an C.
Trang 1Cdu 4: M o t mach dao dong l i tifdng gom cuon cam t h u a n c6 do t\X
cam 4fj,H va m o t t u dien c6 dien dung bien doi tCf 10 p F den 640 p F
Lay n' = 10 Chu k i dao dong r i e n g cua mach nay c6 gia t r i
A tCr 2.10-^s den 3,6.10 ^s B tCf 4.10-^s den 2,4.10-^s
C tCr 4.10-^s den 3,2.10's D tii 2.10-^s den 3.10-^s
Giai
Chu k i dao dong dien tCf T = 2nVLC
T a c o : T i = 27I7LC^ = 2W4.10-'.10.10-" =2W4.10-" «4.10-'s
Ta = 27t7LC7 = 2W4.10"".640.10^'- = 327iV4.10"" 3,2.10"'s
Vay chgn dap an C
Cdu 5: K h i electron d quy dao dCfng thuf n t h i nang liitfng ciia nguyen
tijf hidro dUcfc t i n h theo cong thufc E„ - (eV) (n = 1 , 2 , 3, ) K h i
n"
electron trong nguyen tuf hidro chuyen tCf quy dao dCfng n = 3 sang quy
di, J difng n = 2 t h i nguyen tuf hidro phat r a photon ufng v d i bufc xa c6 bifdfc song bkng:
A 0,4350nm B 0,4861^m C 0,657e^im D 0,4102^m
Giai
Ta c6:
hc
9 4 6,'625.10-'\3.10'
-6,576.10"' = 0,6576pm l,889eV 1,889.1,06.10""
Vay chgn dap an C
Cdu 6: Cho ba h a t n h a n X, Y va Z c6 so nuclon tirong ufng l a Ax, Ay, Az
vdfi Ax = 2AY = 0,5Az Biet nang iLfdng l i e n k e t cua tCrng h a t n h a n tLforng ufng la A Ex, A E y , AEz vdri A E z < A E x < AEy Sap xep cac h a t
nhan nay theo thuf txi t i n h ben vufng giam dan l a :
A Y, X, Z B Y , Z, X C X , Y , Z D Z, X, Y
Giai
Theo de bai A , = 2Ay = 0,5A, ^ 2A^ = 4Ay = A ,