The difference of pressure between the inside and outside of a liquid drop is
p = T × r
p = T/r
p = T/2r
p = 2T/r
Correct Answer :
D. p = 2T/r
Related Questions
Choose the wrong statement
Any weight, floating or immersed in a liquid, is acted upon by a buoyant force
Buoyant force is equal to the weight of the liquid displaced
The point through which buoyant force acts, is called the center of buoyancy
Center of buoyancy is located above the center of gravity of the displaced liquid
A flow is called hyper-sonic, if the Mach number is
Less than unity
Unity
Between 1 and 6
None of these
Coefficient of discharge Cd is equal to (where Cc = Coefficient of contraction, Cv = Coefficient of velocity, and Cr = Coefficient of resistance)
Cc × Cv
Cc × Cr
Cv × Cr
Cc/Cr
According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to
The weight of the body
More than the weight of the body
Less than the weight of the body
Weight of the fluid displaced by the body
A channel is said to be of most economical cross-section, if
It gives maximum discharge for a given cross-sectional area and bed slope
It has minimum wetted perimeter
It involves lesser excavation for the designed amount of discharge
All of the above
Buoyant force is
Resultant force acting on a floating body
Equal to the volume of liquid displaced
Force necessary to keep a body in equilibrium
The resultant force on a body due to the fluid surrounding it
Resultant pressure of the liquid in the case of an immersed body acts through
Centre of gravity
Centre of pressure
Metacentre
Centre of buoyancy
A tank of uniform cross-sectional area (A) containing liquid upto height (H1) has an orifice of cross-sectional area (a) at its bottom. The time required to empty the tank completely will be
(2A√H₁)/(Cd × a√2g)
(2AH₁)/(Cd × a√2g)
(2AH₁3/2)/(Cd × a√2g)
(2AH₁²)/(Cd × a√2g)
Center of pressure compared to e.g. is
Above it
Below it
At same point
Above or below depending on area of body
A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. The total pressure on the wall acts at a distance __________ from the liquid surface.
H/3
H/2
2H/3
3H/4
The velocity of jet of water travelling out of opening in a tank filled with water is proportional to
Head of water (h)
h²
V/T
h/2
When the flow parameters at any given instant remain same at every point, then flow is said to be
Quasi-static
Steady state
Laminar
Uniform
The efficiency of power transmission through pipe is (where H = Total supply head, and hf = Head lost due to friction in the pipe)
(H - hf )/H
H/(H - hf )
(H + hf )/H
H/(H + hf )
Two pipe systems can be said to be equivalent, when the following quantities are same
Friction loss and flow
Length and diameter
Flow and length
Friction factor and diameter
Cavitation will begin when
The pressure at any location reaches an absolute pressure equal to the saturated vapour pressure of the liquid
Pressure becomes more than critical pressure
Flow is increased
Pressure is increased
A vertically immersed surface is shown in the below figure. The distance of its centre of pressure from the water surface is 
(bd²/12) + x
(d²/12 x) + x
b²/12 + x
d²/12 + x
According to Chezy's formula, the discharge through an open channel is (where A = Area of flow, C = Chezy's constant, m = Hydraulic mean depth, and i = Uniform slope in bed)
A × √(m × i)
C × √(m × i)
AC × √(m × i)
mi × √(A × C)
The speed of sound in a ideal gas varies directly as its
Absolute temperature
Temperature
Density
Modulus of elasticity
A piece of wood having weight 5 kg floats in water with 60% of its volume under the liquid. The specific gravity of wood is
0.83
0.6
0.4
0.3
Euler's number is the ratio of __________ force to pressure force.
Inertia
Gravity
Viscous
None of these
The buoyancy depends upon the
Weight of the liquid displaced
Pressure with which the liquid is displaced
Viscosity of the liquid
Compressibility of the liquid
The specific weight of sea water is __________ that of pure water.
Same as
Less than
More than
None of these
The length AB of a pipe ABC in which the liquid is flowing has diameter (d1) and is suddenly enlarged to diameter (d2) at B which is constant for the length BC. The loss of head due to sudden enlargement is
(v₁ - v₂)²/g
(v₁² - v₂²)/g
(v₁ - v₂)²/2g
(v₁² - v₂²)/2g
A flow in which the volume of a fluid and its density does not change during the flow is called _________ flow.
Incompressible
Compressible
Viscous
None of these
When the Mach number is between __________ the flow is called super-sonic flow.
1 and 2.5
2.5 and 4
4 and 6
1 and 6
The flow in which conditions do not change with time at any point, is known as
One dimensional flow
Uniform flow
Steady flow
Turbulent flow
The pressure of a liquid measured with the help of a Piezometer tube is
Vacuum pressure
Gauge pressure
Absolute pressure
Atmospheric pressure
The discharge through a wholly drowned orifice is given by (where H1 = Height of water (on the upstream side) above the top of the orifice, H2 = Height of water (on the downstream side) above the bottom of the orifice, and H = Difference between two water levels on either side of the orifice)
Q = Cd × bH₁ × √(2gh)
Q = Cd × bH2 × √(2gh)
Q = Cd × b (H2 - H1) × √(2gh)
Q = Cd × bH × √(2gh)
The velocity corresponding to Reynold number of 2800, is called
Sub-sonic velocity
Super-sonic velocity
Lower critical velocity
Higher critical velocity
A piece of metal of specific gravity 7 floats in mercury of specific gravity 13.6. What fraction of its volume is under mercury?
0.5
0.4
0.515
0.5