The law of continuity states that,

A v= A’ v’

As taken in the figure,

Where,

Area of ‘Pipe a’ is A

Area of ‘Pipe b’ is A’

Speed of the fluid in the ‘pipe a’ = v

Speed of the fluid in the ‘pipe b’ = v_’

The law thus states that if the area of cross section in the Venturimeter is small, the speed of the flowing liquid through the part will be more.

And the Bernoulli’s principle states that if the speed is more around a part, the pressure will be less.

The pressure is directly proportional to the height.

In the figure, the area A’ is less than area A, Thus, the speed in the is higher and thus the height of the in ‘pipe b’ must be higher.

The figure ‘a’ is the incorrect option.