Vay chgn dap an D.
Trang 1D i l m sang S qua L2 cho a n h S ' each L2 mot doan:
da = 12 + 24 = 36 (cm)
Muon chum t i a qua L2 la chum song song t h i S ' p h a i n a m of tieu
diem F2 cua L2, hay tieu cU cua L2 la £2 = da = 36cm = 0,36m
1 1 25
Dp t u cua thau k i n h L2 phai c6 gia t r i : D = j = Q~3^ ~ "9"
(^^°P^-Viay chon dap an C
Cdu 45: Mot k i n h h i e n v i quang hoc gom vat k i n h v a t h i k i n h c6 tieu
cLf Ian luot la 0,5 c m v a 4 cm K h o a n g each giufa v a t k i n h v a t h i k i n h
b^ng 20 c m M o t ngUdi m ^ t k h o n g c6 t a t , c6 d i e m ctfc « a n each m ^ t
25 cm, suT dung k i n h h i e n v i nay de quan sat mot v a t nho D o bpi giac
cua k i n h k h i ng^m ehCrng d v6 cufc la:
A 19,75 B 25,25 C 193,75 D 250,25
Giai
T a c6: D = 25cm, fi = 0,5cm, {2 = 4cm, 5 = 20 - 4,5 = 15,5cm
Do boi giac cua k i n h k h i ngim ehCfng d v6 cifc 1^: G = = 193,75
h h Vay chgn dap an C
Cdu 46: M o t t i a sang dcn sic truyen tii m o i trir&ng (1) c6 ehiet suat
tuyet doi n i sang m o i trifcfng (2) c6 ehiet suat tuyet doi na t h i t i a khiic
xa lech x a phap tuyen hcfn t i a tdi H i e n ti/png p h a n x a toan phan c6
the xay ra k h o n g neu chieu t i a sang theo chieu tii m o i trifcfng (2) sang
moi trifcfng (1)?
A K h o n g the, v i m o i triX&ng (2) ehiet quang hcfn naoi triTcfng (1)
B Co the, v i m o i trifofng (2) chie't quang k e m m o i triTcfng (1)
C C o the, v i m o i trifcfng (2) ehiet quang hcfn m o i triTcfng (1)
D K h o n g the, v i m o i trUcfng (2) ehiet quang k e m m o i tri/orng (1)
Giai
K h o n g the, v i m o i tnicfng (2) ehiet quang k e m m o i trifcfng (1)
Vay chgn dap an D
Cdu 47: M o t ngifcfi can t h i c6 diem cife can c^ch m ^ t 10 cm, diem ciic
vi§n each m ^ t 50 cm, deo k i n h eo do tu - 2 diop s6t mAt t h i n h i n ro vat:
A each mkt 50 c m m ^ mSt khong can dieu tiet
B d gan n h a t cdch m ^ t mot doan 10 cm
C or x a v6 ciTe nhiftig m ^ t van can dieu tiet
D d x a v6 cue m a m ^ t khong can dieu tiet