Question

An equiconvex lens has a focal length of 0.10m and radius of one curved surface 0.12m find the refractive of the material of the convex lens

Answer 1

☆ɢɪᴠᴇɴ -

ꜰᴏᴄᴀʟ ʟᴇɴɢᴛʜ - 0.10 ᴍᴇᴛʀᴇ

ʀᴀᴅɪᴜꜱ ᴏꜰ ᴄᴜʀᴠᴀᴛᴜʀᴇ - 0.12 ᴍᴇᴛʀᴇ

ᴇQᴜɪᴄᴏɴᴠᴇx ʟᴇɴꜱ

☆ꜰɪɴᴅ -

ʀᴇꜰʀᴀᴄᴛɪᴠᴇ ɪɴᴅᴇx ᴏꜰ ᴍᴀᴛᴇʀɪᴀʟ ᴏꜰ ᴄᴏɴᴠᴇx ʟᴇɴꜱ.

ꜱᴏʟᴜᴛɪᴏɴ - ʟᴇɴꜱ ᴍᴀᴋᴇʀ'ꜱ ᴇQᴜᴀᴛɪᴏɴ ʜᴏʟᴅꜱ ʀᴇʟᴀᴛɪᴏɴꜱʜɪᴘ ʙᴇᴛᴡᴇᴇɴ ʀᴇꜰʀᴀᴄᴛɪᴠᴇ ɪɴᴅᴇx, ꜰᴏᴄᴀʟ ʟᴇɴɢᴛʜ ᴀɴᴅ ʀᴀᴅɪɪ ᴏꜰ ᴄᴜʀᴠᴀᴛᴜʀᴇ ᴏꜰ ᴛʜᴇ ᴛᴡᴏ ꜱᴘʜᴇʀᴇꜱ ᴜꜱᴇᴅ ɪɴ ʟᴇɴꜱᴇꜱ.

☆ᴛʜᴇ ᴇQᴜᴀᴛɪᴏɴ ɪꜱ -

1/ꜰ = (ᴍᴇᴜ-1) {(1/ʀ1)-(1/ʀ2)}

ɪɴ ᴛʜᴇ ᴇQᴜᴀᴛɪᴏɴ, ꜰ ꜱᴛᴀɴᴅꜱ ꜰᴏʀ ꜰᴏᴄᴀʟ ʟᴇɴɢᴛʜ, ᴍᴇᴜ ɪꜱ ʀᴇꜰʀᴀᴄᴛɪᴠᴇ ɪɴᴅᴇx, ʀ1 ᴀɴᴅ ʀ2 ʀᴇꜰᴇʀꜱ ᴛᴏ ʀᴀᴅɪᴜꜱ ᴏꜰ ᴄᴜʀᴠᴀᴛᴜʀᴇ.

ꜱɪɴᴄᴇ Qᴜᴇꜱᴛɪᴏɴ ꜱᴛᴀᴛᴇꜱ ʟᴇɴꜱ ᴛᴏ ʙᴇ ᴇQᴜɪᴄᴏɴᴠᴇx ʜᴇɴᴄᴇ, ʀ1 = ʀ2 = ʀ.

ᴛʜᴇʀᴇꜰᴏʀᴇ, ɴᴇᴡ ꜰᴏʀᴍᴜʟᴀ ᴡɪʟʟ ʙᴇ,

1/ꜰ = (ᴍᴇᴜ-1)*(2/ʀ)

ᴋᴇᴇᴘɪɴɢ ᴠᴀʟᴜᴇꜱ ɪɴ ᴇQᴜᴀᴛɪᴏɴ-

1/0.10*(0.12/2) = (ᴍᴇᴜ-1)

0.06/0.10 = ᴍᴇᴜ-1

0.6 = ᴍᴇᴜ-1

ᴍᴇᴜ = 1.6

ʜᴇɴᴄᴇ, ʀᴇꜰʀᴀᴄᴛɪᴠᴇ ɪɴᴅᴇx ᴏꜰ ᴍᴀᴛᴇʀɪᴀʟ ᴏꜰ ᴄᴏɴᴠᴇx ʟᴇɴꜱ ɪꜱ 1.6.