1. Which of the following phenomena of light are involved in the formation of a rainbow ( )
A) Refraction, dispersion
B) Refraction, dispersion and total internal reflection
C) Reflection, refraction and dispersion
D) Dispersion, scattering and total internal reflection
2. A diverging mirror is ( )
A) a plane mirror B) a convex mirror
C) a concave mirror D) All of the above
3. Froth flotation is method used for the purification of ( )
A) Oxide B) Carbonate
C) Sulphide D) Nitrate
4. The material used in preparation of diodes, transistors and integrated circuits are ( )
A) Carbon B) Lead C) Nichrome D) Silicon, Germanium
5. Which is used in cough syrups ( )
A) Methanol B) Ethanol C) Gasoline D) Iodine
Answers: 1-B; 2-B; 3-C; 4-D; 5-B.