Questions

Optical fiber works on the principle of total internal reflection.

The Total Internal Reflection is the phenomenon in which the complete reflection of a light ray reaching an interface with a less dense medium when the angle of incidence exceeds the critical angle.

There are two types of water hardness: temporary and permanent hardness. Temporary hardness is due to the presence of calcium hydrogen carbonate Ca(HCO3)2(aq) and magnesium hydrogen carbonate Mg(HCO3)2(aq).

‘Poetry’ needs to be replaced with ‘Poem’ to make the sentence contextually correct. ‘Poetry’ is a literary work; ‘Poem’ is a piece of writing. Here, the writing is being talked about. Thus, the correct sentence would be, ‘The writer of this poem is Wordsworth’.