55) SONAR is based on the principle of.
(A) echo
(B) resonance
(C) reverberation
(D) any one of the above
56) According to which of the following scientist, '' an increase in pressure at any point inside a liquid at rest is transmitted equally and without any change in all directions to every other point in the liquid'' .
(A) Boyle
(B) Pascal
(C) Archemedes
(D) Newton