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 |
A square plate of 0.1 m side moves parallel to a second plate with a velocity of 0.1 m/s, both plates being immersed in water. If the viscous force is 0.002 N and the coefficient of viscosity is 0.01 poise, then the distance between the plates in m is:
1. | 0.1 | 2. | 0.05 |
3. | 0.005 | 4. | 0.0005 |
A spherical ball of radius \(r\) is falling in a viscous fluid of viscosity \(\eta\) with a velocity \(v.\) The retarding viscous force acting on the spherical ball is:
1. | inversely proportional to \(r\) but directly proportional to velocity \(v.\) |
2. | directly proportional to both radius \(r\) and velocity \(v.\) |
3. | inversely proportional to both radius \(r\) and velocity \(v.\) |
4. | directly proportional to \(r\) but inversely proportional to \(v.\) |
The pans of a physical balance are in equilibrium. If Air is blown under the right hand pan then the right hand pan will:
1. | Move up | 2. | Move down |
3. | Move erratically | 4. | Remain at the same level |
A sniper fires a rifle bullet into a gasoline tank making a hole 53.0 m below the surface of gasoline. The tank was sealed at 3.10 atm. The stored gasoline has a density of 660 . The velocity with which gasoline begins to shoot out of the hole will be:
1. | 27.8 ms-1 | 2. | 41.0 ms-1 |
3. | 9.6 ms-1 | 4. | 19.7 ms-1 |