1.A spherical drop of water has radius 1 mm If
surface tension of water is 70 * 10-3 N/m
difference of pressures between inside and out
side of the spherical drop is
a) \[35 N\diagup m^{2}\]
b) \[70 N\diagup m^{2}\]
c) \[140 N\diagup m^{2}\]
d) Zero
Explanation:
2. The pressure at the bottom of a tank containing a
liquid does not depend on
a) Acceleration due to gravity
b) Height of the liquid column
c) Area of the bottom surface
d) Nature of the liquid
Explanation:
3. In capillary pressure below the curved surface of
water will be
a) Equal to atmospheric
b) Equal to upper side pressure
c) More than upper side pressure
d) Lesser than upper side pressure
Explanation: Lesser than upper side pressure
4. Two soap bubbles of radii \[r_{1}\] and \[r_{2}\] equal to 4 cm
and 5 cm are touching each other over a common
surface \[S_{1}S_{2}\] (shown in figure). Its radius will be
a) 4 cm
b) 20 cm
c) 5 cm
d) 4.5 cm
Explanation:
5. The pressure inside a small air bubble of radius
0.1 mm situated just below the surface of water
will be equal to [ Take surface tension of water \[70\times10^{-3}Nm^{-1}\] and
atmospheric pressure = \[1.013\times10^{5}Nm^{-2}\] ]
a) \[2.054\times10^{3}Pa\]
b) \[1.027\times10^{3}Pa\]
c) \[1.027\times10^{5}Pa\]
d) \[2.054\times10^{5}Pa\]
Explanation:
6. Two bubbles A and B \[\left(A>B\right)\] are joined through a
narrow tube. Then
a) The size of A will increase
b) The size of B will increase
c) The size of B will increase until the pressure equals
d) None of these
Explanation:
7. Two soap bubbles have different radii but their
surface tension is the same. Mark the correct
statement
a) Internal pressure of the smaller bubble is
higher than the internal pressure of the larger
bubble
b) Pressure of the larger bubble is higher than
the smaller bubble
c) Both bubbles have the same internal pressure
d) None of the above
Explanation:
8. If the excess pressure inside a soap bubble is
balanced by oil column of height 2 mm, then the
surface tension of soap solution will be (r = 1 cm
and density d = 0.8 gm/cc)
a) 3.9 N/m
b) \[3.9 ×10^{-2} N/m\]
c) \[3.9 ×10^{-3} N/m\]
d) 3.9 dyne/m
Explanation:
9. The excess pressure in a soap bubble is thrice that
in other one. Then the ratio of their volume is
a) 1 : 3
b) 1 : 9
c) 27 : 1
d) 1 : 27
Explanation:
10. When two capillary tubes of different diameters
are dipped vertically, the rise of the liquid is
a) Same in both the tubes
b) More in the tube of larger diameter
c) Less in the tube of smaller diameter
d) More in the tube of smaller diameter
Explanation:
