J J Science Academy - Test Paper

1. The cross-sectional area of a large tank is $(0.5 m^2)$. It has an opening near the bottom having cross-sectional area $(1 cm^2)$. A load of 20 kg is applied on the water at the top. The velocity of water coming out of the opening, at the time when the height of water level is 50 cm above the bottom, si nearly (Take $(g=10 m s^{-2}))$

(1) $(1.3 m s^{-1})$ (2) $(3.3 m s^{-1})$ (3) $(5.3 m s^{-1})$ (4) $(7.3 m s^{-1})$

2. The vertical sections of the wing of a fan are shown in Fig. 6. Maximum upthrust is in

3. Bernoulii's principle is based on law of conservation of

(1) Mass (2) Momentum (3) Energy (4) None of above

4. The velocity of air layers above the airplane is $(v_1)$ and below is $(v_2)$. Then for the plane to remain in vertical equilibrium,

(1) $(V_1=V_2)$ (2) $(V_1>V_2)$ (3) $(V_1 (4) (2) or (3)

5. The dimensions of velocity head are

(1) $([M^0 L^1 T^{-1}])$ (2) $([M^0 L^{-1} T^0])$ (3) $([M^0 L^1 T^{-2}])$ (4) $([M^0 L^1 T^0])$

6. In a horizontal flow, the pressure head decreases. It means

(1) Gravitational head decreases (2) Velocity head increases (3) Gravitational head increases (4) Velocity head decreases

7. A person standing close to a fast moving train, is likely to be pushed towards train. This can be explained by

(1) Benoulli's principle (2) Toricelli's principle (3) Law of continuity (4) Poisecuille's law

8. Venturimeter works on

(1) Benoulli's principle (2) Toricelli's principle (3) Law of continuity (4) Both (1) and (3)

9. In a streamlined flow the power due to pressure difference is equal to

(1) Pressure in magnitude (2) Pressure × density (3) Pressure x mass of liquid flowing per second (4) Pressure * volume of liquid flowing per second.

10. Which of the following is used in designing atomizers?

(1) Pascal's law of liquids (2) Archimede's principle (3) Torricelli's principle (4) Bernoulli's theorem.

11. Water is flowing through a horizontal tube. The pressure of the liquid in the portion where velocity is $(1 cm s^{-1})$ is 2 cm of Hg . What will be the pressure in the portion where velocity is $(2 cm s^{-1})$ ?

(1) $(0.5 cm of Hg)$ (2) $(2 cm of Hg)$ (3) $(4 cm of Hg)$ (4) None of the above

12. The pressure energy per unit volume of a liquid of density $(\rho)$ when the pressure is $(p)$ is numerically equal to

(1) $(p)$ (2) $(p / \rho)$ (3) $(\rho p)$ (4) None of the above

13. Bernoulli's theorem is a consequence of conservation of

(1) Energy (2) Linear momentum (3) Angular momentum (4) Mass

14. An L-shaped glass tube is just immersed in flowing water such that its opening is pointing against flowing water. If the speed of water current is v , then

(1) The water in the tube rises to height $(\frac{v^2}{2 g})$ (2) The water in the tube rises to height $(\frac{g}{2 v^2})$ (3) The water in the tube does not rise at all (4) None of the above

15. Air is streaming past a horizontal air plane wing such that its speed is $(120 m / s)$ over the upper surface and $(90 m / s)$ at the lower surface. If the density of air is $(1.3 kg per metre^3)$ 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) $(4.0950 pascal)$

16. Which of the following is a consequence of conservation of energy?

(1) Archimedes` principle (2) Pascal's law (3) Bernoulli's theorem (4) Torricelli's theorem