Question

what is focal length​

Answer 1

Answer:

the distance between the centre of the lenses and curved mirror is known as focal length

Answer 2

Answer:

$\huge{\underline{\underline{\mathfrak{answer}}}} \\ distance \: between \: the \: focus \: and \: the \\ optical \: center \: or \: pole \: is \: called \: focal \\ length \\ \\ \huge{\underline{\underline{\mathfrak{mark \: as \: brainliest}}}}</p><p></p><p>$