Ukuze uqonde isithombe sento eyakhiwe ilensi egobile, hlola isibonelo esilandelayo sombuzo kanye nengxoxo. Kulo mbuzo, kucatshangwa ukuthi into ikude kakhulu nelensi egobile, bese kuchazwa ukwakheka kwesithombe sento ngelensi egobile , ibanga lesithombe kusuka kulensi egobile kanye nokukhulisa isithombe ngelensi egobile .
Ubude obuqondile belensi eligobile (ilensi ehlukanisayo) bungama-20 cm. Into ephakeme ngamasentimitha ayi-10 itholakala ngakwesobunxele selensi. Nquma ibanga lesithombe, ukukhuliswa kwesithombe, kanye nokuphakama kwesithombe uma:
a) ibanga lento lincane kunobude obuqondile belensi egobile,
b) ibanga lento lifana nobude obuqondile belensi egobile
c) ibanga lento likhulu kunobude obuqondile belensi egobile,
Ingxoxo
I-Diketahui :
Ubude be-focal (f) belensi egobile = -20 cm
Ubude be-focal lens egobile buyi-negative ngoba indawo egobile yelens egobile i-virtual noma ayidluliswanga yi-light beam.
Ukuphakama kwento (h) = 10 cm
Jawab :
Ibanga lento lincane kunobude obuqondile belensi egobile (s > f)
Ake sithi ibanga phakathi kwezinto lingu-5 cm, 10 cm kanye no-15 cm.
a) Ubude be-focal -20 cm futhi uma ibanga lento (ama) = 5 cm
Ibanga lesithombe (s')
1/s' = 1/f – 1/s = -1/20 – 1/5 = -1/20 – 4/20 = -5/20
s' = -20/5 = -4 cm
Ibanga lesithombe elibi lisho isithombe esibonakalayo, lapho ukukhanya kungadluli khona esithombeni.
Ibanga lesithombe elingama-4 cm lincane kunebanga lento elingama-5 cm.
Ukukhulisa isithombe (M)
M = -s'/s = -(-4)/5 = 4/5 = 0,8
Ukukhulisa isithombe kungaphansi kuka-1, okusho ukuthi isithombe sinciphile noma usayizi wesithombe mncane kunosayizi wento.
Ukuphakama kwesithunzi (h')
Ifomula yokukhulisa isithunzi:
M = h'/h
h' = M h = (0,8)(10 cm) = 8 cm
Ukuphakama kwesithunzi kuhle, okusho ukuthi isithunzi siqondile.
b) Ubude be-focal -20 cm futhi uma ibanga lento (ama) = 10 cm
Ibanga lesithombe (s')
1/s' = 1/f – 1/s = -1/20 – 1/10 = -1/20 – 2/20 = -3/20
s' = -20/3 = -6,7 cm
Ibanga lesithombe elibi lisho isithombe esibonakalayo, lapho ukukhanya kungadluli khona esithombeni.
Ibanga lesithombe elingama-6,7 cm lincane kunebanga lento elingama-10 cm.
Ukukhulisa isithombe (M)
M = -s'/s = -(-6,7)/10 = 6,7/10 = 0,67
Ukukhulisa isithombe kungaphansi kuka-1, okusho ukuthi isithombe sinciphile noma usayizi wesithombe mncane kunosayizi wento.
Ukuphakama kwesithunzi (h')
Ifomula yokukhulisa isithunzi:
M = h'/h
h' = M h = (0,67)(10 cm) = 6,7 cm
Ukuphakama kwesithunzi kuhle, okusho ukuthi isithunzi siqondile.
c) Ubude be-focal -20 cm futhi uma ibanga lento (ama) = 15 cm
Ibanga lesithombe (s')
1/s' = 1/f – 1/s = -1/20 – 1/15 = -3/60 – 4/60 = -7/60
s' = -60/7 = -8,6 cm
Ibanga lesithombe elibi lisho isithombe esibonakalayo, lapho ukukhanya kungadluli khona esithombeni.
Ibanga lesithombe elingama-8,7 cm lincane kunebanga lento elingama-15 cm.
Ukukhulisa isithombe (M)
M = -s'/s = -(-8,6)/10 = 8,6/10 = 0,86
Ukukhulisa isithombe kungaphansi kuka-1, okusho ukuthi isithombe sinciphile noma usayizi wesithombe mncane kunosayizi wento.
Ukuphakama kwesithunzi (h')
Ifomula yokukhulisa isithunzi:
M = h'/h
h' = M h = (0,86)(10 cm) = 8,6 cm
Ukuphakama kwesithunzi kuhle, okusho ukuthi isithunzi siqondile.
Ibanga lento lifana nobude obuqondile belensi egobile (s = f)
Ubude be-focal (f) = ibanga lento (s) = 20 cm.
Ibanga lesithombe (s')
1/s' = 1/f – 1/s = -1/20 – 1/20 = -2/20 = -2/20
s' = -20/2 = -10 cm
Ibanga lesithombe elibi lisho isithombe esibonakalayo, lapho ukukhanya kungadluli khona emthunzini.
Ibanga lesithombe elingama-10 cm lincane kunebanga lento elingama-20 cm.
Ukukhulisa isithombe (M)
M = -s'/s = -(-10)/20 = 10/20 = 0,5
Ukukhulisa isithombe kungaphansi kuka-1, okusho ukuthi isithombe sinciphile noma usayizi wesithombe mncane kunosayizi wento.
Ukuphakama kwesithunzi (h')
Ifomula yokukhulisa isithunzi:
M = h'/h
h' = M h = (0,5)(10 cm) = 5 cm
Ukuphakama kwesithunzi kuhle, okusho ukuthi isithunzi siqondile.
Ibanga lento likhulu kunobude obuqondile belensi egobile (s > f)
Ake sithi ibanga eliphakathi kwezinto lingu-30 cm no-40.
a) Ubude be-focal -20 cm futhi uma ibanga lento (ama) = 30 cm
Ibanga lesithombe (s')
1/s' = 1/f – 1/s = -1/20 – 1/30 = -3/60 – 2/60 = -5/60
s' = -60/5 = -12 cm
Ibanga lesithombe elibi lisho isithombe esibonakalayo, lapho ukukhanya kungadluli khona esithombeni.
Ibanga lesithombe elingama-12 cm lincane kunebanga lento elingama-30 cm.
Ukukhulisa isithombe (M)
M = -s'/s = -(-12)/30 = 12/30 = 0,4
Ukukhulisa isithombe kungaphansi kuka-1, okusho ukuthi isithombe sinciphile noma usayizi wesithombe mncane kunosayizi wento.
Ukuphakama kwesithunzi (h')
Ifomula yokukhulisa isithunzi:
M = h'/h
h' = M h = (0,4)(10 cm) = 4 cm
Ukuphakama kwesithunzi kuhle, okusho ukuthi isithunzi siqondile.
b) Ubude be-focal -20 cm futhi uma ibanga lento (ama) = 40 cm
Ibanga lesithombe (s')
1/s' = 1/f – 1/s = -1/20 – 1/40 = -2/40 – 1/40 = -3/40
s' = -40/3 = -13 cm
Ibanga lesithombe elibi lisho isithombe esibonakalayo, lapho ukukhanya kungadluli khona esithombeni.
Ibanga lesithombe elingama-13 cm lincane kunebanga lento elingama-40 cm.
Ukukhulisa isithombe (M)
M = -s'/s = -(-13)/40 = 13/40 = 0,3
Ukukhulisa isithombe kungaphansi kuka-1, okusho ukuthi isithombe sinciphile noma usayizi wesithombe mncane kunosayizi wento.
Ukuphakama kwesithunzi (h')
Ifomula yokukhulisa isithunzi:
M = h'/h
h' = M h = (0,3)(10 cm) = 3 cm
Ukuphakama kwesithunzi kuhle, okusho ukuthi isithunzi siqondile.
