(a)(i) Define each of the following terms as it relates to converging lenses (i) focal length; (ii) optical Centre.
(iii) Draw a ray diagram to illustrate how a converging lens is used to produce a virtual image of an object.
(b)(i) Name the primary colors of light. (ii) Match each primary color to its corresponding complementary color.
(c) A ray passes symmetrically through a glass prism of angle 60° and refractive index of 1.5. Calculate the angle of: (i) incidence; (ii) minimum deviation.
Explanation
(a)(i) Definition of Terms: (1) Focal length of a converging lens is the distance between the optical centre and the principal focus.
(2) The geometric centre of the lens through which rays of light pass undev1ated. OR Optical centres of a converging lens is a point in the lens through which the principal axıs and light rays pass undeviated.
(b)(i) Primary Colours of Light: (1) Red (2) Blue (3) Green (b)(ii) Match each primary colour to list Corresponding complementary colour:
(1) Red >Cyan (2) BIlue>Yellow (3) Green Magenta
(c)(i) Angle of Incidence: n = \(\frac{Sin i }{Sin r}\);
1.5 = \(\frac{Sin i }{Sin 30}\);
i = 48.6°
Angle of Min Deviation
n = sin \(\frac{D min + A}{2}\)/ [Sin 1/2]
1.5 = Sin \(\frac{D min + A}{2}\)/[sin30]°
D min = 37.2°