Equation of continuity is based on:
1. | Conservation of mass |
2. | Conservation of energy |
3. | Conservation of angular momentum |
4. | None of these |
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 the siphon is 1.5 gm/cc. The pressure difference between the point P and S will be:
1. | 105 N / m | 2. | 2 × 105 N / m |
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. The 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 |
The value of g at a place decreases by 2%. Then, the barometric height of mercury:
1. | increases by 2%. | 2. | decreases by 2%. |
3. | remains unchanged. | 4. | sometimes increases and sometimes decreases. |
A barometer kept in a stationary elevator reads 76 cm. If the elevator starts accelerating up, the reading will be:
1. | zero. | 2. | equal to 76 cm. |
3. | more than 76 cm. | 4. | less than 76 cm. |
A body is just floating on the surface of a liquid. The density of the body is the same as that of the liquid. The body is slightly pushed down. What will happen to the body?
1. | It will slowly come back to its earlier position |
2. | It will remain submerged, where it was left |
3. | It will sink |
4. | It will come out violently |
If two pieces of metal when immersed in a liquid have equal upthrust on them, then:
1. | Both pieces must have equal weights |
2. | Both pieces must have equal densities |
3. | Both pieces must have equal volumes |
4. | Both are floating in the same depth |
The following fig. shows the flow of liquid through a horizontal pipe. Three tubes A, B and C are connected to the pipe. The radii of the tubes A, B and C at the junction are respectively 2 cm, 1 cm and 2 cm. It can be said that the:
1. | Height of the liquid in the tube A is maximum |
2. | Height of the liquid in the tubes A and B is the same |
3. | Height of the liquid in all the three tubes is the same |
4. | Height of the liquid in the tubes A and C is the same |
There is a hole in the bottom of a tank having water. If the total pressure at the bottom is 3 atm ( ), then the velocity of water flowing from the hole is:
1. | \(\sqrt{400}~~\text{m/s}\) | 2. | \(\sqrt{600}~~\text{m/s}\) |
3. | \(\sqrt{60}~~\text{m/s}\) | 4. | None of these |