Question

Define the following terms
1. focal length
2.pole
3.focus

Answer 1

Answer:

1.focal length=The distance between the pole and focus point i.e. PF = f

2.Pole : The geometrical central point of the reflecting spherical surface. (aperture), denoted by (P).

3.Focus point : The point on the principal axis, where all parallel rays meet after reflection is called as Principal Focus or Focus. It is denoted by letter ‘F’.

Answer 2

Answer:

1.focal lenght- the distance between the centre of a lens or curved mirror known as focus lenght.

2.pole-a long,slender,rounded piece of wood or metal.

3.focus-the centre of the interest or activity.

Explanation:

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