A spherical drop of water has 1 mm radius. If the surface tension of water is 70 ×10-3 Nm-1, then difference of pressure between inside and outside of the spherical drop is
35 Nm-2
70 Nm-2
140 Nm-2
zero
A vessel contains oil (density = 0.8 g cm-3 ) over mercury (density = 13.6 g cm-3 ). A homogeneous sphere floats with half of its volume immersed in mercury and the other half in oil. The density of the material (in g cm-3 ) is
3.3
6.4
7.2
2.8
A wooden block is taken to the bottom of a deep, calm lake of water and then released. It rises up with a
constant acceleration
decreasing acceleration
constant velocity
decreasing velocity
Two capillaries of lengths L and 2 L and of radii R and 2 R respectively are connected in series. The net rate of flow of fluid through them will (Given, rate of the flow through single capillary, ) be
The radii of two drops are in the ratio of 3 : 2, their terminal velocities are in the ratio
9 : 4
2 : 3
3 : 2
2 : 9
A glass tube of uniform internal radius (r) has a value separating the two identical ends. Initially, the value is in a tightly closed position. End 1 has a hemispherical soap bubble of radius r. End 2 has sub-hemi-spherical soap bubbles as shown in figure. Just after opening the valve,
air from end 1 flows towards end 2. No change in the volume of the soap bubbles.
air from end 1 flows towards end 2. Volume of the soap bubbles at end 1 decreases.
no changes occur
air from end 2 flows towards end 2. Volume of the soap bubble at end 1 increases.
An object is moving through the liquid. The viscous damping force acting on its is proportional to the velocity. Then dimensions of constant of proportionality are
[ ML-1 T--1 ]
[ MLT--1 ]
[ ML0 LT-1 ]
[ ML0 T--1 ]
The radii of two soap bubbles are R1 and R2 . If they coaleasce, the radius of curvature of the common surface will be :
R1 R2
R2 - R1
