AP EAMCET201923 Apr 2019Morning ShiftPhysicsMechanical Properties of FluidsActual
Two tubes of same length and diameters (4 ~mm ) and (8 ~mm ) are joined together to form a U-shaped tube open at both the ends. If the U-tube contains water, then the difference between the levels of water in the two limbs of the tube is (Surface tension of water at the temperature of experiment is (7.3 10⁻² Nm ⁻¹ ), angle of contact (=0^ ), density of water (=1.0 10^3 ~kg ~m ⁻³ ) and acceleration due to gravity (=10
Options
- A(3.65 ~mm )
- B(36.5 ~mm )
- C(0.365 ~mm )
- D(365 ~mm )
Correct answer
A. (3.65 ~mm )
Step-by-step solution
A figure of U-shaped tube of different diameter is given below, Given, radius of first tube, (R₁=2 ~mm ) and radius of second tube, (R₂=4 ~mm ). density of water, ( =1.0 10^3 ~kg - m ⁻³ ) Since, the tube is open at both the ends. So, (p_A=p_B=p₀ ) (atmospheric pressure) Pressure in capillary tube (B ), (p_B= 2 T R₂ =p₀ ) [Here, (T ) = Surface tension of water] Similarly pressure at capillary tube (A ), (p_A= 2 T R₁ =p₀ ) Hence, for same height (O O^ ), ( aligned - g x+ 2 T R₁ & = 2 T R₂ x & = 2 T g [ 1 R₁ - 1 R₂ ]