JEE Main & Advanced Physics Fluid Mechanics, Surface Tension & Viscosity / द्रव यांत्रिकी, भूतल तनाव और चिपचिपापन Question Bank

done Pressure Difference Total Questions - 30

• question_answer1)
  A soap bubble assumes a spherical surface. Which of the following statement is wrong          [NCERT 1976]
  A)
  The soap film consists of two surface layers of molecules back to back done clear
  B)
              The bubble encloses air inside it done clear
  C)
              The pressure of air inside the bubble is less than the atmospheric pressure; that is why the atmospheric pressure has compressed it equally from all sides to give it a spherical shape done clear
  D)
                  Because of the elastic property of the film, it will tend to shrink to as small a surface area as possible for the volume it has enclosed done clear
  View Solution play_arrow

• question_answer2)
  If two soap bubbles of different radii are in communication with each other              [NCERT 1980; MP PMT/PET 1988; AIEEE 2004]
  A)
  Air flows from larger bubble into the smaller one done clear
  B)
              The size of the bubbles remains the same done clear
  C)
              Air flows from the smaller bubble into the large one and the larger bubble grows at the expense of the smaller one done clear
  D)
              The air flows from the larger done clear
  View Solution play_arrow

• question_answer3)
  The surface tension of soap solution is \[25\times {{10}^{-3}}\,N{{m}^{-1}}\].  The excess pressure inside a soap bubble of diameter 1 cm is                                  [AIIMS 1987]
  A)
  10 Pa   done clear
  B)
              20 Pa done clear
  C)
              5 Pa     done clear
  D)
               None of the above done clear
  View Solution play_arrow

• question_answer4)
  When two soap bubbles of radius \[{{r}_{1}}\]and \[{{r}_{2}}\] \[({{r}_{2}}>{{r}_{1}})\] coalesce, the radius of curvature of common surface is [MP PMT 1996]
  A)
              \[{{r}_{2}}-{{r}_{1}}\]        done clear
  B)
              \[\frac{{{r}_{2}}-{{r}_{1}}}{{{r}_{1}}{{r}_{2}}}\] done clear
  C)
              \[\frac{{{r}_{1}}{{r}_{2}}}{{{r}_{2}}-{{r}_{1}}}\]      done clear
  D)
              \[{{r}_{2}}+{{r}_{1}}\] done clear
  View Solution play_arrow

• question_answer5)
  The excess pressure due to surface tension in a spherical liquid drop of radius r is directly proportional to [MP PMT 1987; KCET 2000]
  A)
                      \[r\]      done clear
  B)
              \[{{r}^{2}}\] done clear
  C)
              \[{{r}^{-1}}\]           done clear
  D)
              \[{{r}^{-2}}\] done clear
  View Solution play_arrow

• question_answer6)
  A long cylindrical glass vessel has a small hole of radius 'r' at its bottom. The depth to which the vessel can be lowered vertically in the deep water bath (surface tension T) without any water entering inside is                              [MP PMT 1990]
  A)
              \[4T/\rho rg\]    done clear
  B)
              \[3T/\rho rg\] done clear
  C)
   \[2T/\rho rg\]   done clear
  D)
              \[T/\rho rg\] done clear
  View Solution play_arrow

• question_answer7)
  If the surface tension of a soap solution is 0.03 MKS units, then the excess of pressure inside a soap bubble of diameter 6 mm over the atmospheric pressure will be
  A)
  Less than\[40N/{{m}^{2}}\]                done clear
  B)
              Greater than \[40N/{{m}^{2}}\] done clear
  C)
              Less than\[20N/{{m}^{2}}\]                done clear
  D)
              Greater than \[20N/{{m}^{2}}\] done clear
  View Solution play_arrow

• question_answer8)
  The excess of pressure inside a soap bubble than that of the outer pressure is [MP PMT 1989; BHU 1995; MH CET 2002; RPET 2003; AMU (Engg.) 2000]
  A)
              \[\frac{2T}{r}\]           done clear
  B)
              \[\frac{4T}{r}\] done clear
  C)
              \[\frac{T}{2r}\]           done clear
  D)
              \[\frac{T}{r}\] done clear
  View Solution play_arrow

• question_answer9)
  The pressure of air in a soap bubble of 0.7cm diameter is 8 mm of water above the pressure outside. The surface tension of the soap solution is [MP PET 1991; MP PMT 1997]
  A)
              \[100dyne/cm\] done clear
  B)
              \[68.66dyne/cm\] done clear
  C)
              \[137dyne/cm\] done clear
  D)
                       \[150dyne/cm\] done clear
  View Solution play_arrow

• question_answer10)
  Pressure inside two soap bubbles are 1.01 and 1.02 atmospheres. Ratio between their volumes is [MP PMT 1991]
  A)
  102 : 101         done clear
  B)
               \[{{\left( 102 \right)}^{3}}:{{\left( 101 \right)}^{3}}\] done clear
  C)
              8 : 1     done clear
  D)
               2 : 1 done clear
  View Solution play_arrow

• question_answer11)
  A capillary tube of radius r is dipped in a liquid of density r and surface tension S. If the angle of contact is q, the pressure difference between the two surfaces in the beaker and the capillary
  A)
              \[\frac{S}{r}\cos \theta \] done clear
  B)
                       \[\frac{2S}{r}\cos \theta \] done clear
  C)
              \[\frac{S}{r\cos \theta }\]        done clear
  D)
              \[\frac{2S}{r\cos \theta }\] done clear
  View Solution play_arrow

• question_answer12)
  The radii of two soap bubbles are r1 and r2. In isothermal conditions, two meet together in vaccum. Then the radius of the resultant bubble is given by [MP PMT 2001; RPET 1999; EAMCET 2003]
  A)
              \[R=({{r}_{1}}+{{r}_{2}})/2\] done clear
  B)
                       \[R={{r}_{1}}({{r}_{1}}{{r}_{2}}+{{r}_{2}})\] done clear
  C)
              \[{{R}^{2}}=r_{1}^{2}+r_{2}^{2}\] done clear
  D)
                       \[R={{r}_{1}}+{{r}_{2}}\] done clear
  View Solution play_arrow

• question_answer13)
  The adjoining diagram shows three soap bubbles A, B and C prepared by blowing the capillary tube fitted with stop cocks, S1, S2 and S3. With stop cock S closed and stop cocks S1, S2 and S3 opened                     [CPMT 1988]
  A)
  B will start collapsing with volumes of A and C increasing done clear
  B)
              C will start collapsing with volumes of A and B increasing done clear
  C)
              C and A both will start collapsing with the volume of B increasing done clear
  D)
                  Volumes of A, B and C will become equal at equilibrium done clear
  View Solution play_arrow

• question_answer14)
  When a large bubble rises from the bottom of a lake to the surface, its radius doubles. If atmospheric pressure is equal to that of column of water height H, then the depth of lake is [AIIMS 1995; AFMC 1997]
  A)
  H         done clear
  B)
              2H done clear
  C)
              7H       done clear
  D)
              8H done clear
  View Solution play_arrow

• question_answer15)
  A soap bubble in vacuum has a radius of 3 cm and another soap bubble in vacuum has a radius of 4 cm. If the two bubbles coalesce under isothermal condition, then the radius of the new bubble is              [MP PMT/PET 1998; JIPMER 2000]
  A)
  2.3 cm done clear
  B)
                       4.5 cm done clear
  C)
              5 cm    done clear
  D)
   7 cm done clear
  View Solution play_arrow

• question_answer16)
  The volume of an air bubble becomes three times as it rises from the bottom of a lake to its surface. Assuming atmospheric pressure to be 75 cm of Hg and the density of water to be 1/10 of the density of mercury, the depth of the lake is                                 [AMU 1995]
  A)
  5 m      done clear
  B)
   10 m done clear
  C)
              15 m    done clear
  D)
   20 m done clear
  View Solution play_arrow

• question_answer17)
  Excess pressure of one soap bubble is four times more than the other. Then the ratio of volume of first bubble to another one is  [CPMT 1997; MH CET 2000]
  A)
  1 : 64   done clear
  B)
               1 : 4 done clear
  C)
              64 : 1   done clear
  D)
               1 : 2 done clear
  View Solution play_arrow

• question_answer18)
  There are two liquid drops of different radii. The excess pressure inside over the outside is     [JIPMER 1999]
  A)
  More in the big drop    done clear
  B)
              More in the small drop done clear
  C)
              Equal in both drops     done clear
  D)
              There is no excess pressure inside the drops done clear
  View Solution play_arrow

• question_answer19)
  If pressure at half the depth of a lake is equal to 2/3 pressure at the bottom of the lake then what is the depth of the lake    [RPET 2000]
  A)
  10m     done clear
  B)
              20m done clear
  C)
              60m     done clear
  D)
              30m done clear
  View Solution play_arrow

• question_answer20)
  If the radius of a soap bubble is four times that of another, then the ratio of their pressures will be   [AIIMS 2000]
  A)
  1 : 4     done clear
  B)
              4 : 1 done clear
  C)
              16 : 1   done clear
  D)
              1 : 16 done clear
  View Solution play_arrow

• question_answer21)
  A spherical drop of water has radius 1 mm If surface tension of water is \[70\times {{10}^{-3}}\]N/m  difference of pressures between inside and out side of the spherical drop is [CPMT 2000; AIIMS 2000]
  A)
              \[35\,N/{{m}^{-2}}\] done clear
  B)
                       \[70\,N/{{m}^{2}}\] done clear
  C)
              \[140\,\,N/{{m}^{2}}\] done clear
  D)
                       Zero done clear
  View Solution play_arrow

• question_answer22)
  The pressure at the bottom of a tank  containing a liquid does not depend on              [Kerala (Engg.) 2001]
  A)
  Acceleration due to gravity done clear
  B)
              Height of the liquid column done clear
  C)
              Area of the bottom surface done clear
  D)
              Nature of the liquid done clear
  View Solution play_arrow

• question_answer23)
  In capillary pressure below the curved surface of water will be                        [RPET 2001]
  A)
  Equal to atmospheric done clear
  B)
              Equal to upper side pressure done clear
  C)
              More than upper side pressure done clear
  D)
              Lesser than upper side pressure done clear
  View Solution play_arrow

• question_answer24)
  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                              [MP PMT 2002]
  A)
  4 cm    done clear
  B)
              20 cm done clear
  C)
              5 cm    done clear
  D)
              4.5 cm done clear
  View Solution play_arrow

• question_answer25)
  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 \[70\times {{10}^{-3}}N{{m}^{-1}}\] and atmospheric pressure = \[1.013\times {{10}^{5}}N{{m}^{-2}}\]] [AMU (Med.) 2002]
  A)
              \[2.054\times {{10}^{3}}Pa\] done clear
  B)
                       \[1.027\times {{10}^{3}}Pa\] done clear
  C)
              \[1.027\times {{10}^{5}}Pa\] done clear
  D)
                       \[2.054\times {{10}^{5}}Pa\] done clear
  View Solution play_arrow

• question_answer26)
  Two bubbles A and B \[(A>B)\] are joined through a narrow tube. Then       [UPSEAT 2001; Kerala (Med.) 2002]
  A)
  The size of A will increase done clear
  B)
              The size of B will increase done clear
  C)
              The size of B will increase until the pressure equals done clear
  D)
              None of these done clear
  View Solution play_arrow

• question_answer27)
  Two soap bubbles have different radii but their surface tension is the same. Mark the correct statement                                               [MP PMT 2004]
  A)
  Internal pressure of the smaller bubble is higher than the internal pressure of the larger bubble done clear
  B)
  Pressure of the larger bubble is higher than the smaller bubble done clear
  C)
  Both bubbles have the same internal pressure done clear
  D)
  None of the above done clear
  View Solution play_arrow

• question_answer28)
  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)        [J & K CET 2004]
  A)
  3.9 N/m done clear
  B)
                       \[3.9\text{ }\times {{10}^{2}}N/m\] done clear
  C)
              \[3.9\text{ }\times {{10}^{3}}N/m\] done clear
  D)
  3.9 dyne/m done clear
  View Solution play_arrow

• question_answer29)
  In Jager's method, at the time of bursting of the bubble              [RPET 2002]
  A)
  The internal pressure of the bubble is always greater than external pressure done clear
  B)
  The internal pressure of the bubble is always equal to external pressure done clear
  C)
  The internal pressure of the bubble is always less than external pressure done clear
  D)
  The internal pressure of the bubble is always slightly greater than external pressure done clear
  View Solution play_arrow

• question_answer30)
  The excess pressure in a soap bubble is thrice that in other one. Then the ratio of their volume is  [RPMT 2003; CPMT 2001]
  A)
  1 : 3     done clear
  B)
              1 : 9 done clear
  C)
              27 : 1   done clear
  D)
  1 : 27 done clear
  View Solution play_arrow