Question
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Answer (Detailed Solution Below)
Option 1 : $-60\ \text{cm}$ / $-60\ \text{cm}$
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Detailed Solution
सही उत्तर $-60\ \text{cm}$ / $-60\ \text{cm}$ है।
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prepsnap.in • Part -AQuestion:
A plano-concave lens of radius of curvature $30\ \text{cm}$ ($n = 1.5$) has focal length / $30\ \text{cm}$ वक्रता त्रिज्या वाले समतलावतल लेंस ($n = 1.5$) की फोकस दूरी है
1.
$-60\ \text{cm}$ / $-60\ \text{cm}$
2.
$+60\ \text{cm}$ / $+60\ \text{cm}$
3.
$-30\ \text{cm}$ / $-30\ \text{cm}$
4.
$+30\ \text{cm}$ / $+30\ \text{cm}$
Correct Answer: $-60\ \text{cm}$ / $-60\ \text{cm}$
$1/f = (1.5 - 1)(-1/30) = -1/60$, so $f = -60\ \text{cm}$, the negative sign denoting a diverging lens. / $1/f = (1.5 - 1)(-1/30) = -1/60$, अतः $f = -60\ \text{cm}$; ऋण चिह्न अपसारी लेंस दर्शाता है।
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