Density

Q. Air is streaming past a horizontal air plane wing such that its speed in 120 m/s over the upper surface and 90 m/s at the lower surface. If the density of air is 1.3 kg per $metr{e}^3$ and the wing is 10 m long and has an average width of 2 m, then the difference of the pressure on the two sides of the wing of

1. 4095.0 Pascal
2. 409.50 Pascal
3. 40.950 Pascal
4. 4.0950

Q.

A 10 H.P. motor pumps out water from a well of depth 20m and fills a water tank of volume 22380 litres at a height of 10m from the ground. The running time of the motor to fill the empty water tank is ($g=10m{s}^{-2}$)

1. 15 minutes

2. 20 minutes

3. 5 minutes

4. 10 minutes

Q.

The terminal velocity of a steel ball of 4 mm in diameter falling through a glycerin of viscosity 3.3 poise, given relative density of steel is 8, relative density of glycerin is 1.3 is

1. 1.77 cm s^-1

2. 13.23 cm s^-1

3. 17.47 cm s^-1

4. 1.47 cm s^-1

Q. For maximum range R, an orifice is made at the depth of h from the upper surface of incompressible liquid. If the height of liquid column in open vessel is 100 m then the value of h is

Q. A pendulum clock becomes 5 sec fast each day at temperature at 15C and becomes 10 sec slower each day at temperature 30C The temperature at which clock gives correct tim

Q. The density of a piece of clay is 1.8 in C.G.S system of units. The corresponding value in S.l unit system is(1) 18000(3) 180(2) 1800(4) 18

Q. One fine day upto 12:00 noon, a pendulum and a digital clock show same time at 30^oC, IF sudenly temp. is increased to 50^oC THEN at 3pm it is decreased to 20^oC, find THE TIME WHEN BOTH CLOCKS WILL SHOW the saame time agaiin.

Q. The volume of a $500\text{g}$ sealed packet is $350{\text{cm}}^3$. Will the packet float or sink in a saturated salt solution, if the density of the solution is $1.2{\text{g cm}}^{-3}$?

1. The packet will sink
2. The packet will float
3. The packet will float submerged
4. None of these

Q. 22. Is density a tensor quantity?

Q. There are two holes one each along the opposite sides of a wide rectangular tank.The cross section of each hole is 0.01m2 and the vertical distance between holes is one metre.The tank is filled with water .The net force on the tank in newton when the water flows out of the holes is 1)100 2)200 3)300 4)400

Q.

If a sample of metal weighs 210 gm in air, 180 gm in water and 120 gm in a liquid:

1. Relative density of metal is 3

2. Relative density of metal is 7

3. Relative density of liquid is 10

4. Relative density of liquid is (1/3)

Q. two cubical blocks identical in dimensions float in water in such a way that 1st block floats with half part immersed in water and second block floats with 3/4 of its volume inside the water The ratio of densities of blocks

Q.

A 5.2 g of a substance occupies 1.11 cm³. Its density to appropriate significant figure is:

1. 4.68

2. 4.685

3. 4.7

4. 4.6845

Q. A \(100~\text{W}\) electric bulb was switched on in a \(2.5~\text{m}\times 3~\text{m}\times3~\text{m}\) size thermally insulated room having a temperature of \(20~^{\circ}\text{C}\). The room temperature at the end of \(24~\text{hours}\) will be (Assume, air to be ideal in nature)

[Data required: specific heat of air at constant volume \(c_v=0.717~\text{kJ/kgK}\) and density of air, \(\rho =1.2~\text{kg/m}^3\)]

Q. A block of steel of size 5×5×5 cm^3 is weighed in water.If relative density of steel is 7, the apparent weight is 1. 6×5×5×5gwt2. 4×4×4×7gwt3. 5×5×5×7gwt4. 4×4×46gwt

Q. \(70~\text{cal}\) of heat is required to raise the temperature of \(2\) moles of an ideal gas at constant pressure from \(30^\circ~\text{C}\) to \(35^\circ~\text{C}\). The amount of heat required to raise the temperature of the same gas through same range of temperature (\(30^\circ~\text{C}\) to \(35^\circ~\text{C}\)) at constant volume is
Given \((\gamma=7/5)\)

Q.

What is heavier on the surface of Earth: 1 m³ cotton or 1 m³ of Iron?{provided: ρ_iron>ρ_cotton}

1. cotton

2. Iron

3. Both will have equal weight

4. Both will have equal mass

Q. two solid pieces one of steel and the other of aluminium when immersed completely in water have equal weights.when the solid pieces weighed in air

Q. Two substances of relative densities ${\rho }_1$ and ${\rho }_2$ are mixed in equal volumes and the relative density of the mixture is $4$. When they are mixed in equal masses, the relative density of the mixture is $3$. The values of ${\rho }_1$ and ${\rho }_2$ are

1. ${\rho }_1=6$ and ${\rho }_2=2$
2. ${\rho }_1=3$ and ${\rho }_2=5$
3. ${\rho }_1=12$ and ${\rho }_2=4$
4. None of these

Q. Can a pendulum clock be used in earth satellite?

Q. if the string of a conical pendulum makes an angle θ with horiontal, then square of its time period is proportional t

Q. a block of wood floats in water with 4/5 of its volume submereged but it just floats in another liq the density of liq

Q. Two substances of densities $d_1$ and $d_2$ are mixed in equal volume and the relative density of mixture is 4. When they are mixed in equal masses, the relative density of mixture is 3. Then $d_1=$ ________ $\frac{gm}{cc}$.

1. 6
2. 8
3. 12
4. 4

Q. In a conical pendulum the length of the string is l and Φ is the angle of string with horizontal. The time period of revolution i

Q. If L_1 is the length of a imperfectly adjusted second pendulum which gains n second in one hour and L_{} is the length of one which looses n seconds in 1 hour in the same place find the true lenght the second pendulum?

Q. A vessel containing $100\text{g}$ water at $0^{\circ }C$ is left in the middle of a room. In $15$ minutes, the temperature of the water rises by $2^{\circ }C$. When an equal amount of ice is placed in the vessel, it melts in $10$ hours. The specific heat of fusion of ice is
(Take specific heat capacity of water as $1\text{cal/g.deg}$)

1. $50\text{cal/g}$
2. $80\text{cal/g}$
3. $70\text{cal/g}$
4. $40\text{cal/g}$

Q. 5. A solid sphere has a radius of 3 CM and a mass of 0.06kg .what is the relative density of the sphere.

Q.

A 2.16 g of a substance occupies 1.5 cm³. Its density to appropriate significant figure is:

1. 1.44

2. 1.444

3. 1.5

4. 1.4

Q. If the linear density of a rod of length L varies as λ = kx where k is a constant and x is the distance of any point from one end placed at origin. The distance of centre of mass from x = 0 is

Q. 31. what is lattice enthalpy ?