Physics Practice Test – Density, Relative Density, Upthrust (Questions with Answers and Explanations)

The density of a certain oil on frying becomes 0.4 kgm^-3 with volume of 20 m³. What will be its initial volume when its initial density is 0.8 kgm^-3 assuming no loss of oil due to spillage? (JAMB 2010)

A. 8 m³     B. 5 m³     C. 12 m³     D. 10 m³

A hydrometer is an instrument used in measuring _____ (JAMB 2010)

A. relative humidity of a liquid
B. relative density of a liquid
C. vapour pressure of a fluid
D. density of liquid

The terminal velocity of a ball-bearing falling through a viscous fluid is reached when the ____ (JAMB 2009)

A. upthrust is equal to the weight of the ball
B. ball accelerates uniformly
C. upthrust is equal to the velocity of the ball
D. velocity is uniform

The relative density of a liquid is the ratio of the _______ (JAMB 2016)

A. mass of water to the mass of an equal volume of liquid
B. upthrust in the liquid to the upthrust in water
C. density of water to density of the liquid
D. upthrust in water to the upthrust in the liquid

An object weighs 22 kg in water and 30 kg in air. What is the upthrust excited by the liquid on the object? [g = 10ms^-2] (JAMB 2011)

A. 50 N   B. 520 N   C. 220 N   D. 80 N