Question

please answer this to be a BRAINIEST!​

Answer 1

Answer:

The needle is placed 50 cm in front of the lens

The power of the lens is +4D

Explanation:

let h' be the image size and h be the object size and let m be the magnification

v=50cm

h'=h (given)

h'=mh

m=1

m=v/u

m=1=50/u

u=50/1=>-50 cm

1/v-1/u=1/f

1/50-(1/-50)=1/f

2/50=1/f

25cm=f

P=1/f

P=1/0.25

P=+4D

pls mark brainliest

Answer 2

Answer:

ʀᴇғᴇʀ ᴛᴏ ᴛʜɪs ᴀᴛᴛᴀᴄʜᴍᴇɴᴛ...

ᴄᴢ ᴍʏ ᴡʀɪᴛɪɴɢ ɪs ʙᴀᴅ...

ʜᴏᴘᴇ ᴛʜɪs ʜᴇʟᴘs ʏᴏᴜ...

ʏᴏᴜʀs sɪɴᴄᴇʀᴇʟʏ

ᴊᴀʟᴀʏ....