Two light balls are suspended as shown in the figure. When a stream of air passes through the space between them,the distance between the balls will

The pans of a physical balance are in equilibrium. Air is blown under the right hand pan; then the right hand pan will

Water flows through the tube shown. The cross-sectional areas of the wide and narrow parts are $5 \text{ cm}^2$ and $2 \text{ cm}^2$,respectively. The rate of flow is $500 \text{ cm}^3/\text{s}$. Find the difference in the mercury level of the $U$-tube in $\text{cm}$.

Consider a water tank as shown in the figure. Its cross-sectional area is $0.4\, m^{2}$. The tank has an opening $B$ near the bottom whose cross-sectional area is $1\, cm^{2}$. $A$ load of $24\, kg$ is applied on the water at the top. When the height of the water level is $40\, cm$ above the bottom,the velocity of water coming out of the opening $B$ is $v\, ms^{-1}$. The value of $v$,to the nearest integer,is ......$m/s$. [Take value of $g$ to be $10\, ms^{-2}$]

Water flows through a frictionless duct with a cross-section varying as shown in the figure. The pressure $p$ at points along the axis is represented by:

Water containing air bubbles flows without turbulence through a horizontal pipe which has a region of narrow cross-section. In this region,the bubbles