A) Polarization and interference

B) Diffraction and dispersion

C) Multiple refraction and dispersion

D) Multiple reflection and interference

(A) centre of gravity

(B) centripetal force

(C) centrifugal force

(D) moment of force

(A) metallic

(B) ionic

(C) molecular

(D) covalent-network

(A) virtual and upright

(B) virtual and inverted

(C) real and inverted

(D) real and upright

(A) nuclear fusion

(B) nuclear fission

(C) radioactivity

(D) artificial radioactivity

(A)  at an elevated position

(B) falling

(C) at rest

(D) moving

(A) 300 m

(B) 30 m

(C) 3 m

(D) 0.3 m

(A) microwave

(B) optical fiber

(C) radio wave

(D) all are operating at nearly the same propagation speed

(A) its velocity never changes

(B) its speed always changes

(C) its direction always changes

(D) its speed may or may not change

(A) air to glass

(B) air to water

(C) water to glass

(D) diamond to glass