465. According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to __________________?

A. the weight of the body
B. more than the weight of the body
C. less than the weight of the body
D. weight of the fluid displaced by the body
✅ The correct answer is option D.

466. Which one of the following statement is correct ?

A. Radiant energy expressed in Joules, is the energy associated with electromagnetic radiation
B. The rate of transfer of radiant energy is called flux and is expressed in watts
C. The radiant energy which falls upon a surface is termed as irradiance
D. All of these
✅ The correct answer is option D.

468. For similarity, in addition to models being geometrically similar to prototype, the following in both cases should also be equal__________________?

A. ratio of inertial force to force due to viscosity
B. ratio of inertial force to force due to gravitation
C. ratio of inertial force to force due to surface tension
D. all the four ratios of inertial force to force due to viscosity, gravitation, surface tension, and elasticity
✅ The correct answer is option D.