Question

A glass prism is able to produce a spectrum when white light passes through it but a glass slab does not produce any spectrum. Explain why is it so?

Answer 1

For dispersion, the two refracting surfaces must be inclined to each other as in case of prism. In rectangular glass slab, the refracting surfaces are parallel to each other. So, dispersion cannot occur. This is due to fact that the rectangular glass slab can be considered as equivalent of two identical prisms in inverted position placed in an inverted position with respect to each other. The deviation and dispersion produced by the second inverted prism is equal and opposite to that produced by the first prism.

For dispersion, the two refracting surfaces must be inclined to each other as in case of prism. In rectangular glass slab, the refracting surfaces are parallel to each other. So, dispersion cannot occur. This is due to fact that the rectangular glass slab can be considered as equivalent of two identical prisms in inverted position placed in an inverted position with respect to each other. The deviation and dispersion produced by the second inverted prism is equal and opposite to that produced by the first prism.

For dispersion, the two refracting surfaces must be inclined to each other as in case of prism. In rectangular glass slab, the refracting surfaces are parallel to each other. So, dispersion cannot occur. This is due to fact that the rectangular glass slab can be considered as equivalent of two identical prisms in inverted position placed in an inverted position with respect to each other. The deviation and dispersion produced by the second inverted prism is equal and opposite to that produced by the first prism. Therefore, there will neither be dispersion, nor deviation, Le. second inverted prism recombines the , colour to give a white light parallel to the incident ray again and will undergo only lateral displacement. Hence, rectangular glass slab cannot produce any spectrum.

hope it helps you

please follow and mark as brainliest

Answer 2

Solution 1 :

ᴡʜᴇɴ ᴀ ʀᴀʏ ᴏꜰ ʟɪɢʜᴛ ᴘᴀꜱꜱᴇꜱ ꜰʀᴏᴍ ᴏɴᴇ ᴍᴇᴅɪᴜᴍ ᴛᴏ ᴛʜᴇ ᴏᴛʜᴇʀ ᴍᴇᴅɪᴜᴍ, ᴛʜᴇ ʀᴇꜰʀᴀᴄᴛɪᴏɴ ᴏꜰ ʟɪɢʜᴛ ᴄᴀᴜꜱᴇꜱ.ɪɴ ᴀ ᴘʀɪꜱᴍ ᴛʜᴇ ꜰᴀᴄᴇꜱ ᴀʀᴇ ɪɴᴄʟɪɴᴇᴅ ᴡɪᴛʜ ᴇᴀᴄʜ ᴏᴛʜᴇʀ ᴀɴᴅ ɴᴏᴛ ᴘᴀʀᴀʟʟᴇʟ ᴛᴏ ᴇᴀᴄʜ ᴏᴛʜᴇʀ. ʜᴇɴᴄᴇ, ᴡʜᴇɴ ᴀ ʀᴀʏ ᴏꜰ ᴡʜɪᴛᴇ ʟɪɢʜᴛ ᴘᴀꜱꜱᴇꜱ ᴛʜʀᴏᴜɢʜ ᴛʜᴇ ᴏɴᴇ ꜰᴀᴄᴇ ᴏꜰ ᴀ ᴘʀɪꜱᴍ, ᴛʜᴇ ᴡʜɪᴛᴇ ʟɪɢʜᴛ ᴜɴᴅᴇʀɢᴏᴇꜱ ᴅɪꜱᴘᴇʀꜱɪᴏɴ ᴀɴᴅ ꜱᴇᴘᴀʀᴀᴛᴇꜱ ɪɴᴛᴏ ɪᴛꜱ ꜱᴇᴠᴇɴ ᴄᴏɴꜱᴛɪᴛᴜᴇɴᴛ ᴄᴏʟᴏʀꜱ.

ᴛʜᴇꜱᴇ ꜱᴇᴠᴇɴ ᴄᴏʟᴏʀꜱ ᴀʀᴇ ᴅɪꜱᴛɪɴᴄᴛ ꜰʀᴏᴍ ᴇᴀᴄʜ ᴏᴛʜᴇʀ ʙᴇᴄᴀᴜꜱᴇ ᴛʜᴇ ᴄᴏɴꜱᴛɪᴛᴜᴇɴᴛ ᴄᴏʟᴏʀꜱ ᴏꜰ ᴛʜᴇ ᴡʜɪᴛᴇ ʟɪɢʜᴛ ᴀʟꜱᴏ ᴜɴᴅᴇʀɢᴏ ʀᴇꜰʀᴀᴄᴛɪᴏɴ. ᴅᴜᴇ ᴛᴏ ᴛʜɪꜱ ʀᴇꜰʀᴀᴄᴛɪᴏɴ, ᴛʜᴇ ꜱᴇᴠᴇɴ ᴄᴏʟᴏʀꜱ ɪɴ ᴛʜᴇ ᴡʜɪᴛᴇ ʟɪɢʜᴛ ᴅᴇᴠɪᴀᴛᴇꜱ ᴡɪᴛʜ ꜱᴏᴍᴇ ᴀɴɢʟᴇ ᴀɴᴅ ᴀᴘᴘᴇᴀʀꜱ ᴅɪꜱᴛɪɴᴄᴛ.ᴡʜᴇɴ ᴛʜᴇꜱᴇ ꜱᴇᴠᴇɴ ᴄᴏʟᴏʀꜱ ᴏꜰ ᴡʜɪᴛᴇ ʟɪɢʜᴛ ᴘᴀꜱꜱ ᴛʜʀᴏᴜɢʜ ᴛʜᴇ ꜱᴇᴄᴏɴᴅ ꜰᴀᴄᴇ ᴏꜰ ᴛʜᴇ ᴘʀɪꜱᴍ, ᴛʜᴇʏ ᴀɢᴀɪɴ ᴜɴᴅᴇʀɢᴏ ʀᴇꜰʀᴀᴄᴛɪᴏɴ ᴀɴᴅ ᴅᴇᴠɪᴀᴛɪᴏɴ ᴄᴀᴜꜱᴇꜱ ᴛʜᴇᴍ ᴛᴏ ʟᴏᴏᴋ ᴅɪꜱᴛɪɴᴄᴛ.

ʙᴜᴛ ɪɴ ᴀ ʀᴇᴄᴛᴀɴɢᴜʟᴀʀ ɢʟᴀꜱꜱ ꜱʟᴀʙ, ᴛʜᴇ ᴏᴘᴘᴏꜱɪᴛᴇ ꜰᴀᴄᴇꜱ ᴏꜰ ᴛʜᴇ ꜱʟᴀʙ ᴀʀᴇ ᴘᴀʀᴀʟʟᴇʟ ᴛᴏ ᴇᴀᴄʜ ᴏᴛʜᴇʀ.ᴡʜᴇɴ ᴀ ʀᴀʏ ᴏꜰ ᴡʜɪᴛᴇ ʟɪɢʜᴛ ᴘᴀꜱꜱᴇꜱ ᴛʜʀᴏᴜɢʜ ᴛʜᴇ ʀᴇᴄᴛᴀɴɢᴜʟᴀʀ ɢʟᴀꜱꜱ ꜱʟᴀʙ, ɪᴛ ᴜɴᴅᴇʀɢᴏᴇꜱ ᴅɪꜱᴘᴇʀꜱɪᴏɴ ᴀɴᴅ ꜱᴇᴘᴀʀᴀᴛᴇꜱ ɪɴᴛᴏ ꜱᴇᴠᴇɴ ᴄᴏɴꜱᴛɪᴛᴜᴇɴᴛ ᴄᴏʟᴏʀꜱ. ʙᴜᴛ ᴡʜᴇɴ ᴛʜᴇꜱᴇ ᴅɪꜱᴘᴇʀꜱᴇᴅ ᴄᴏʟᴏʀꜱ ᴏꜰ ʟɪɢʜᴛ ᴇᴍᴇʀɢᴇ ꜰʀᴏᴍ ᴛʜᴇ ᴏᴘᴘᴏꜱɪᴛᴇ ꜰᴀᴄᴇ ᴏꜰ ᴛʜᴇ ɢʟᴀꜱꜱ ꜱʟᴀʙ, ᴛʜᴇ ᴇᴍᴇʀɢɪɴɢ ʀᴀʏꜱ ᴏꜰ ʟɪɢʜᴛ ᴀɢᴀɪɴ ᴄᴏᴍʙɪɴᴇ ᴡɪᴛʜ ᴇᴀᴄʜ ᴏᴛʜᴇʀ ᴛᴏ ꜰᴏʀᴍ ᴡʜɪᴛᴇ ʟɪɢʜᴛ ᴀꜱ ᴛʜᴇ ʀᴇꜰʀᴀᴄᴛɪᴏɴ ᴅᴏᴇꜱ ɴᴏᴛ ᴅᴇᴠɪᴀᴛᴇ ᴛʜᴇꜱᴇ ꜱᴇᴠᴇɴ ᴄᴏʟᴏʀꜱ.

ʜᴇɴᴄᴇ, ᴛʜᴇ ʟɪɢʜᴛ ᴇᴍᴇʀɢɪɴɢ ꜰʀᴏᴍ ᴛʜᴇ ꜱᴇᴄᴏɴᴅ ꜰᴀᴄᴇ ᴏꜰ ᴛʜᴇ ɢʟᴀꜱꜱ ꜱʟᴀʙ ᴅᴏᴇꜱ ɴᴏᴛ ᴘʀᴏᴅᴜᴄᴇ ᴀɴʏ ꜱᴘᴇᴄᴛʀᴜᴍ.

Solution 2 :

ᴀ ɢʟᴀꜱꜱ ᴘʀɪꜱᴍ ɪꜱ ᴀʙʟᴇ ᴛᴏ ᴘʀᴏᴅᴜᴄᴇ ᴀ ꜱᴘᴇᴄᴛʀᴜᴍ , ᴡʜɪᴄʜ ɪꜱ ᴀ ᴘᴀᴛᴄʜ ᴏꜰ ʟɪɢʜᴛ ᴏʙᴛᴀɪɴᴇᴅ ᴅᴜᴇ ᴛᴏ ᴅɪꜱᴘᴇʀꜱɪᴏɴ. ᴛʜɪꜱ ɪꜱ ʙᴇᴄᴀᴜꜱᴇ ᴛʜᴇ ᴏᴘᴘᴏꜱɪᴛᴇ ʀᴇꜰʀᴀᴄᴛɪɴɢ ꜰᴀᴄᴇꜱ ᴏꜰ ᴀ ɢʟᴀꜱꜱ ᴘʀɪꜱᴍ ᴀʀᴇ ɴᴏᴛ ᴘᴀʀᴇʟʟᴀʟ. ᴛʜᴜꜱ, ᴀ ʀᴇᴄᴛᴀɴɢᴜʟᴀʀ ɢʟᴀꜱꜱ ꜱʟᴀʙ ɪꜱ ᴜɴᴀʙʟᴇ ᴛᴏ ᴘʀᴏᴅᴜᴄᴇ ᴀ ꜱᴘᴇᴄᴛʀᴜᴍ ᴅᴜᴇ ᴛᴏ ᴛʜᴇ ʀᴇꜰʀᴀᴄᴛɪɴɢ ꜰᴀᴄᴇꜱ ʙᴇɪɴɢ ᴘᴀʀᴇʟʟᴀʟ ᴛᴏ ᴇᴀᴄʜ ᴏᴛʜᴇʀ.

Solution 3 :

ᴅɪꜱᴘᴇʀꜱɪᴏɴ ᴅᴏᴇꜱ ɴᴏᴛ ᴛᴀᴋᴇ ᴘʟᴀᴄᴇ ɪɴ ɢʟᴀꜱꜱ ꜱʟᴀʙ ᴀꜱ ᴛᴡᴏ ʀᴇꜰʀᴀᴄᴛɪɴɢ ꜱᴜʀꜰᴀᴄᴇꜱ ᴀʀᴇ ᴘᴀʀᴀʟʟᴇʟ. ᴛʜᴇ ʟɪɢʜᴛ ᴅᴏᴇꜱ ɴᴏᴛ ꜱᴘʟɪᴛ ɪɴᴛᴏ ɪᴛꜱ ᴄᴏɴꜱᴛɪᴛᴜᴇɴᴛ ᴄᴏʟᴏᴜʀꜱ.

_____________

$\huge\sf{卄opє \: íт \: 卄єℓρєd :)}$