Answer:
1.(c) 7
2.(d) 900
3.(b) two
4.(c) 0.0007
5.(d)0.0004
Explanation:
(1) White light after reflection through prism splits into 7 colors.
(2) Arabs and Chinese knew about lenses in about 900 AD
(3) There are Two more colors in the spectrum which cannot be seen with naked eye.
(4) Wavelength of red light is 0.0007mm
(5) Wavelength of violet light is 0.0004mm
