From the given diagram, what is the velocity \(v_3?\)
               
1. \(4\) m/s
2. \(3\) m/s
3. \(1\) m/s
4. \(2\) m/s

In a horizontal pipe of non-uniform cross-section, water flows with a velocity of 1 m s${}^{-1}$ at a point where the diameter of the pipe is 20 cm. The velocity of water (m s${}^{-1}$) at a point where the diameter of the pipe is 5 cm is:
1. 8
2. 16
3. 24
4. 32

An incompressible fluid flows steadily through a cylindrical pipe which has a radius \(2r\) at point \(A\) and a radius \(r\) at \(B\) further along the flow direction. If the velocity at point \(A\) is \(v,\) its velocity at point \(B\) is:
1. \(2v\)                               
2. \(v\)
3. \(v/2\)                            
4. \(4v\)

The cylindrical tube of a spray pump has radius \(R,\) one end of which has \(n\) fine holes, each of radius \(r.\) If the speed of the liquid in the tube is \(v,\) then the speed of ejection of the liquid through the holes will be:
1. \(\dfrac{vR^2}{n^2r^2}\)

2. \(\dfrac{vR^2}{nr^2}\)

3. \(\dfrac{vR^2}{n^3r^2}\)

4. \(\dfrac{v^2R}{nr}\)