A body of density 0.7 gm/ floats on a lake of water. The fraction of the body which is outside water is-
1. 30%
2. 70%
3. 25%
4. 50%
A small spherical solid ball is dropped in a viscous liquid. Its journey in the liquid is best described in the figure by:
1. | curve A | 2. | curve B |
3. | curve C | 4. | curve D |
Water flows through a frictionless duct with a cross-section varying as shown in the figure. Pressure p at points along the axis is represented by:
1. | 2. | ||
3. | 4. |
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 |