Water rises to a height h in capillary tube . If the length of capillary tube above the surface of water is made less than h, then
(1) water rises upto the tip of capillary tube and then starts overflowing like a fountain
(2) water rises upto the top of capillary tube and stays there without overflowing
(3) water rises upto a point a little below the top and stays there
(4) water does not rise at all
A certain number of spherical drops of a liquid of radius r coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then:\(\text { Energy }=4 V T\left(\frac{1}{r}-\frac{1}{R}\right) \text { is released } \)
1. | Energy = \(4 V T\left(\frac{1}{r}-\frac{1}{R}\right)\) is released | 2. | Energy =\(3 V T\left(\frac{1}{r}+\frac{1}{R}\right)\) is released |
3. | Energy =\(3 V T\left(\frac{1}{r}-\frac{1}{R}\right)\) is released | 4. | Energy is neither released nor absorbed |
An engine pumps water continuously through a hose. Water leaves the hose with a velocity \(v\) and \(m\) is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?
1. \(\dfrac{1}{2} m v^{3}\)
2. \(m v^{3}\)
3. \(\dfrac{1}{2} m v^{2}\)
4. \(\dfrac{1}{2} m^{2} v^{2}\)
Two bodies are in equilibrium when suspended in water from the arms of a balance. The mass of one body is \(36~\text g\) and its density is \(9~\text{g/cm}^3.\) If the mass of the other is \(48~\text g,\) its density in \((\text{g/cm}^3)\) will be:
1. \(\frac{4}{3}\)
2. \(\frac{3}{2}\)
3. \(3\)
4. \(5\)
An inverted bell lying at the bottom of a lake 47.6 m deep has 50 cm3 of air trapped in it. The bell is brought to the surface of the lake. The volume of the trapped air will be (atmospheric pressure = 70 cm of Hg and density of Hg = 13.6 g/cm3)
(1) 350 cm3
(2) 300 cm3
(3) 250 cm3
(4) 22 cm3
A siphon in use is demonstrated in the following figure. The density of the liquid flowing in siphon is 1.5 gm/cc. The pressure difference between the point P and S will be
(1)
(2)
(3) Zero
(4) Infinity
The height of a mercury barometer is 75 cm at sea level and 50 cm at the top of a hill. Ratio of density of mercury to that of air is . The height of the hill is
(1) 250 m
(2) 2.5 km
(3) 1.25 km
(4) 750 m
Equal masses of water and a liquid of relative density \(2\) are mixed together, then the mixture has a density of:
1. \(\dfrac{2}{3}\)
2. \(\dfrac{4}{3}\)
3. \(\dfrac{3}{2}\)
4. \(3\)
A body of density is counterpoised by Mg of weights of density in air of density d. Then the true mass of the body is
(1) M
(2)
(3)
(4)
The value of g at a place decreases by 2%. The barometric height of mercury
(1) Increases by 2%
(2) Decreases by 2%
(3) Remains unchanged
(4) Sometimes increases and sometimes decreases