Question

a lens is of focal length 40 cm .what is it power?

Answer 1

hello@

here is u r answer##

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answer

focal length , f = 40 cm

power (p) = 100/ f( cm)

100 /40

2.5 D

the power of the lens is +2.5 D.

I hope help u##

### rishu##

@rishu

Answer 2

ʜᴇy ᴜꜱᴇʀ

ʜᴇʀᴇ ɪꜱ yᴏᴜʀ ᴀɴꜱᴡᴇʀ :-

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ꜰᴏᴄᴀʟ ʟᴇɴɢʜᴛ = 40 ᴄᴍ = 0.4 ᴍ

ᴩᴏᴡᴇʀ ( ᴅ ) = 1/ꜰᴏᴄᴀʟ ʟᴇɴɢʜᴛ ( ʟ )

= 1/0.4

= 2.5 ᴅ

ꜱᴏ ᴛʜᴇ ᴩᴏᴡᴇʀ ᴏꜰ ʟᴇɴꜱ ɪꜱ 2.5 ᴅ