A silver ingot weighing 2.1 kg is held by a string so as to be completely immersed in a liquid of relative density 0.8. The relative density of silver is 10.5. The tension in the string in kg-wt is

(1) 1.6                                             

(2) 1.94

(3) 3.1                                           

(4) 5.25

Two solids A and B float in water. It is observed that A floats with half its volume immersed and B floats with 2/3 of its volume immersed. Compare the densities of A and B

(1) 4:3                         

(2) 2:3

(3) 3:4                         

(4) 1:3

The fraction of a floating object of volume ${\mathrm{V}}_0$ and density ${\mathrm{d}}_0$ above the surface of a liquid of density d will be

(1) $\frac{{\mathrm{d}}_0}{\mathrm{d}}$                                       

(2) $\frac{{\mathrm{dd}}_0}{\mathrm{d}+{\mathrm{d}}_0}$

(3) $\frac{\mathrm{d}-{\mathrm{d}}_0}{\mathrm{d}}$                                   

(d) $\frac{{\mathrm{dd}}_0}{\mathrm{d}-{\mathrm{d}}_0}$

Pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and the walls of the containing vessel. This law was first formulated by:

(1) Bernoulli                               

(2) Archimedes

(3) Boyle                                     

(4) Pascal

 A body is just floating on the surface of a liquid. The density of the body is same as that of the liquid. The body is slightly pushed down. What will happen to the body ?
(1) It will slowly come back to its earlier position

(2) It will remain submerged, where it is left

(3) It will sink

(4) It will come out violently

A cork is submerged in water by a spring attached to the bottom of a bowl. When the bowl is kept in an elevator moving with acceleration downwards, the length of spring

(1) Increases                                         

(2) Decreases

(3) Remains unchanged                           

(4) None of these

A solid sphere of density $\mathrm{\eta }$ ( > 1) times lighter than water is suspended in a water tank by a string tied to its base as shown in fig. If the mass of the sphere is m, then the tension in the string is given by:

1. $\left(\frac{\mathrm{\eta }-1}{\mathrm{\eta }}\right)\mathrm{mg}$                              

2. $\mathrm{\eta mg}$

3. $\frac{mg}{\mathrm{\eta }}$                                       

4. $(\mathrm{\eta }-1)\mathrm{mg}$

A hollow sphere of volume V is floating on water surface with half immersed in it. What should be the minimum volume of water poured inside the sphere so that the sphere now sinks into the water ?
(1) V/2                       

(2) V/3

(3) V/4                       

(4) V

A ball whose density is $0.4\times {10}^3 \mathrm{kg}/{\mathrm{m}}^3$ falls into water from a height of 9 cm . To what depth does the ball sink
(a) 9 cm                                   
(b) 6 cm
(c) 4.5 cm                               
(d) 2.25 cm

A boat carrying steel balls is floating on the surface of water in a tank. If the balls are thrown into the tank one by one, how will it affect the level of water?