Kuti unzwisise mufananidzo wechinhu chakagadzirwa ne lenzi yakakombama, tarisa muenzaniso wemubvunzo nekukurukurirana kunotevera. Mumubvunzo uyu, zvinofungidzirwa kuti chinhu chacho chiri kure ne lenzi yakakombama, wobva watsanangura kuumbwa kwemufananidzo wechinhu chacho ne lenzi yakakombama , daro remufananidzo kubva kune lenzi yakakombama uye kukura kwemufananidzo ne lenzi yakakombama .
Kureba kwegirazi rakatetepa (diverging lens) i20 cm. Chinhu chakareba 10 cm chiri kuruboshwe rwegirazi. Sarudza daro remufananidzo, kukura kwemufananidzo, uye kukwirira kwemufananidzo kana:
a) kureba kwechinhu kudiki pane kureba kwefocal ye lens yakakombama,
b) kureba kwechinhu kwakafanana nehurefu hwefocal relenzi yakakombama
c) kureba kwechinhu kwakakura kupfuura kureba kwefocal ye lens yakakombama,
Kukurukurirana
Zvinozivikanwa :
Kureba kwefocal (f) kwelenzi yakakombama = -20 cm
Hurefu hwefocal relenzi yakakombama hauna kunaka nekuti focal point yelenzi yakakombama iri chaiyo kana kuti haina kupfuura nepakati nemwaranzi yechiedza.
Kureba kwechinhu (h) = 10 cm
Jawab :
Daro rechinhu diki pane urefu hwefocal relenzi yakakombama (s > f)
Ngatitii daro rechinhu chacho riri 5 cm, 10 cm uye 15 cm.
a) Kureba kwefocal -20 cm uye kana daro rechinhu (s) = 5 cm
Kureba kwemufananidzo (s')
1/s' = 1/f – 1/s = -1/20 – 1/5 = -1/20 – 4/20 = -5/20
s' = -20/5 = -4 cm
Kureba kwemufananidzo usina kunaka zvinoreva mufananidzo chaiwo, uko chiedza chisingapfuuri nepamufananidzo.
Kureba kwemufananidzo we4 cm kudiki pane kureba kwechinhu che5 cm.
Kukura kwemufananidzo (M)
M = -s'/s = -(-4)/5 = 4/5 = 0,8
Kukura kwemufananidzo kushoma pane 1, zvichireva kuti mufananidzo waderedzwa kana kuti saizi yemufananidzo idiki pane saizi yechinhu chiripo.
Kureba kwemumvuri (h')
Fomura yekuwedzera mumvuri:
M = h'/h
h' = M h = (0,8)(10 cm) = 8 cm
Kureba kwemumvuri kwakanaka, zvichireva kuti mumvuri wakamira.
b) Kureba kwefocal -20 cm uye kana daro rechinhu (s) = 10 cm
Kureba kwemufananidzo (s')
1/s' = 1/f – 1/s = -1/20 – 1/10 = -1/20 – 2/20 = -3/20
s' = -20/3 = -6,7 cm
Kureba kwemufananidzo usina kunaka zvinoreva mufananidzo chaiwo, uko chiedza chisingapfuuri nepamufananidzo.
Kureba kwemufananidzo we6,7 cm kudiki pane kureba kwechinhu che10 cm.
Kukura kwemufananidzo (M)
M = -s'/s = -(-6,7)/10 = 6,7/10 = 0,67
Kukura kwemufananidzo kushoma pane 1, zvichireva kuti mufananidzo waderedzwa kana kuti saizi yemufananidzo idiki pane saizi yechinhu chiripo.
Kureba kwemumvuri (h')
Fomura yekuwedzera mumvuri:
M = h'/h
h' = M h = (0,67)(10 cm) = 6,7 cm
Kureba kwemumvuri kwakanaka, zvichireva kuti mumvuri wakamira.
c) Kureba kwefocal -20 cm uye kana daro rechinhu (s) = 15 cm
Kureba kwemufananidzo (s')
1/s' = 1/f – 1/s = -1/20 – 1/15 = -3/60 – 4/60 = -7/60
s' = -60/7 = -8,6 cm
Kureba kwemufananidzo usina kunaka zvinoreva mufananidzo chaiwo, uko chiedza chisingapfuuri nepamufananidzo.
Kureba kwemufananidzo we8,7 cm kudiki pane kureba kwechinhu che15 cm.
Kukura kwemufananidzo (M)
M = -s'/s = -(-8,6)/10 = 8,6/10 = 0,86
Kukura kwemufananidzo kushoma pane 1, zvichireva kuti mufananidzo waderedzwa kana kuti saizi yemufananidzo idiki pane saizi yechinhu chiripo.
Kureba kwemumvuri (h')
Fomura yekuwedzera mumvuri:
M = h'/h
h' = M h = (0,86)(10 cm) = 8,6 cm
Kureba kwemumvuri kwakanaka, zvichireva kuti mumvuri wakamira.
Kureba kwechinhu kwakafanana nehurefu hwefocal relenzi yakakombama (s = f)
Kureba kwenzvimbo (f) = daro rechinhu (s) = 20 cm.
Kureba kwemufananidzo (s')
1/s' = 1/f – 1/s = -1/20 – 1/20 = -2/20 = -2/20
s' = -20/2 = -10 cm
Kureba kwemufananidzo usina kunaka zvinoreva mufananidzo chaiwo, uko chiedza chisingapfuuri nemumvuri.
Kureba kwemufananidzo we10 cm kudiki pane kureba kwechinhu che20 cm.
Kukura kwemufananidzo (M)
M = -s'/s = -(-10)/20 = 10/20 = 0,5
Kukura kwemufananidzo kushoma pane 1, zvichireva kuti mufananidzo waderedzwa kana kuti saizi yemufananidzo idiki pane saizi yechinhu chiripo.
Kureba kwemumvuri (h')
Fomura yekuwedzera mumvuri:
M = h'/h
h' = M h = (0,5)(10 cm) = 5 cm
Kureba kwemumvuri kwakanaka, zvichireva kuti mumvuri wakamira.
Kureba kwechinhu kwakakura kupfuura kureba kwefocal kwelenzi yakakombama (s > f)
Ngatitii daro riri pakati pezvinhu zviri pakati pe30 cm ne40.
a) Kureba kwefocal -20 cm uye kana daro rechinhu (s) = 30 cm
Kureba kwemufananidzo (s')
1/s' = 1/f – 1/s = -1/20 – 1/30 = -3/60 – 2/60 = -5/60
s' = -60/5 = -12 cm
Kureba kwemufananidzo usina kunaka zvinoreva mufananidzo chaiwo, uko chiedza chisingapfuuri nepamufananidzo.
Kureba kwemufananidzo we12 cm kudiki pane kureba kwechinhu che30 cm.
Kukura kwemufananidzo (M)
M = -s'/s = -(-12)/30 = 12/30 = 0,4
Kukura kwemufananidzo kushoma pane 1, zvichireva kuti mufananidzo waderedzwa kana kuti saizi yemufananidzo idiki pane saizi yechinhu chiripo.
Kureba kwemumvuri (h')
Fomura yekuwedzera mumvuri:
M = h'/h
h' = M h = (0,4)(10 cm) = 4 cm
Kureba kwemumvuri kwakanaka, zvichireva kuti mumvuri wakamira.
b) Kureba kwefocal -20 cm uye kana daro rechinhu (s) = 40 cm
Kureba kwemufananidzo (s')
1/s' = 1/f – 1/s = -1/20 – 1/40 = -2/40 – 1/40 = -3/40
s' = -40/3 = -13 cm
Kureba kwemufananidzo usina kunaka zvinoreva mufananidzo chaiwo, uko chiedza chisingapfuuri nepamufananidzo.
Kureba kwemufananidzo we13 cm kudiki pane kureba kwechinhu che40 cm.
Kukura kwemufananidzo (M)
M = -s'/s = -(-13)/40 = 13/40 = 0,3
Kukura kwemufananidzo kushoma pane 1, zvichireva kuti mufananidzo waderedzwa kana kuti saizi yemufananidzo idiki pane saizi yechinhu chiripo.
Kureba kwemumvuri (h')
Fomura yekuwedzera mumvuri:
M = h'/h
h' = M h = (0,3)(10 cm) = 3 cm
Kureba kwemumvuri kwakanaka, zvichireva kuti mumvuri wakamira.
