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1.	A steel ball-bearing of diameter 3 mm falls through glycerine and covers a distance of 25 cm in 10 sec. The specific gravity of steel and glycerine are `7.8` and `1.26` respectively. What is the viscosity of glycerine. Density of water = 1000 kg `m^(-3)`.
Answer» Correct Answer - `1.282` SI units

2.	Find the terminal velocity acquired by a steel ball of diameter `3.2` mm falling under gravity through an oil of density 920 `"kg m"^(-3)` and viscosity `1.64"N s m"^(-2)`. The density of steel may be taken as 7820 kg `m^(-3)`.
Answer» Correct Answer - `2.35xx10^(-2)ms^(-1)`

3.	Calculate the critical velocity of water through a narrow tube of radius `0.3` mm. Coefficient of viscosity of water is `0.0011` SI units and density of water `1000"kg m"^(-3)`. Take Reynolds number as 1000.
Answer» Correct Answer - `3.67ms^(-1)`

4.	A bubble of air of 2 mm diameter rises in a liquid of viscosity `0.075` SI unit and density 1350 kg per cubic metre. Findthe terminal velocity of the bubble.
Answer» Correct Answer - `3.96xx10^(-2)ms^(-1)`

5.	A horizontal cylindrical vessel with a small orifice of area s is first filled with a liquid of density `rho` and then forced out through it by applying a constant force on the piston closing the cylinder. The time taken is t. The time taken is t. Calculate the work done.
Answer» Correct Answer - `W=(1)/(2)rho(V^(3))/(s^(2)t^(2))`

6.	A vessel fitted with a horizontal capillary tube near its bottom is alternately filled with two liquids of specific gravity `0.8` and `0.9`. It empties itself in 40 and 30 minutes respectively. Calculate the ratio of their coefficient of viscosity.
Answer» Correct Answer - `1.185:1`

7.	In a horizontal oil pipeline of constant cross-sectional area the pressure decrease between two point 300 km apart is 5000 pascal (1 pascal = 1 newton per square meter). What is the loss of energy per unit volume per unit distance? [Hint : Loss in energy `=(P_(1))/(rho)-(P_(2))/(rho)` because `(P)/(rho)` is pressure energy per unit mass and loss in energy per unti volume `=P_(1)-P_(2)`.]
Answer» Correct Answer - `0.01667`J

8.	A vessel of cross-section `20xx10^(-4)` square metres has a capillary tube of length 10 cm and internal radius `0.5` mm at the bottom. It is initially filled with water to a height of 20 cm above the capillary tube. Find the time taken by the vessel to expt one-half of its contents, given that the viscosity of water of `0.001` SI units. Density of water = 1000 kg per cubic metre. [Hint : See example 5]
Answer» Correct Answer - 9 min 36 s

9.	TheThe velocity of flow of water in the main water supply pipe is `1.0ms^(-1)`. What is the velocity in the deliverty pipe if area of cross-section of the supply pipe is 16 times that of the delivery pipe?
Answer» Correct Answer - `16"m s"^(-1)`

10.	A tank is filled with water to a height H. A hole is punched in the wall at a depth h below the water surface. Find the distance x from the wall at which the stream strikes the floor. Could a hole be punched at another depth so that this second stream would have the same range? If so at what depth? For what value of h is range maximum?
Answer» Correct Answer - `sqrt(h(H-h))`; Yes, a distance h above the bottom; h=H/2

11.	The reading of pressure meter attached with a closed pipe is `3.5 xx 10^(5)Nm^(-2)`. On opening the value of the pipe, the reading of the pressure meter is reduced to `3.0 xx 10^(5) Nm^(-2)`. Calculate the speed of the water flowing in the pipe.
Answer» Correct Answer - `10ms^(-1)`

12.	Calculate the velocity of efflux of kerosene form a tank in which the pressure is `4xx10^(5)"N m"^(-2)` above the atmospheric pressure. The density of kerosene is 800 `"kg m"^(-3)` [Hint: `v=sqrt(2gh)`]
Answer» Correct Answer - `31.62ms^(-1)`