J J Science Academy

Subject: Physics Topic: 16. Fluids SubTopic: 16.12 Newton's Formula and Viscosity Test Type: NEET

1) An incompressible liquid is flowing through a uniform cross-sectional tube with velocity $(12 cm / s)$. If the thickness of liquid layer is 0.8 cm, then velocity gradient of flow is

1) 18 s-1 2) $(15 s^{-1})$ 3) $(12 s^{-1})$ 4) $(5 s^{-1})$

2) The SI unit and dimensions of coefficient of viscosity are

1) $(N m^2 / s, [M^1 L^1 T^{-1}])$ 2) $(N s / m, [M^{-1} L T^{-1}])$ 3) $(N s / m^2, [M^1 L T^{-2}])$ 4) $(N s / m^2, [M^1 L^{-1} T^{-1}])$

3) Viscosity is the property of the liquids and gases which are more closely related to .

1) Elasticity 2) Inertia 3) Tension 4) Friction

4) A spaceship entering the earth's atmosphere is likely to catch fire. This is due to

1) The surface tension of air. 2) The viscosity of air. 3) The temperature of the upper atmosphere. 4) The greater proportion of oxygen in the atmosphere at high altitudes.