Question

Which of the following concerning a barometer or manometer is/are true? Pressure is directly proportional to the height of the liquid used in the device. Pressure is directly proportional to the density of the liquid used in the device. Pressure is independent of the acceleration of gravity.

Answer 1

the pressure in a barometer is calculated by using the formula

               pressure=height of liquid above the column *density of liquid used * acceleration due to gravity

                       P=h*d*g (in notation form)

     now first sentece given consider it- pressure directly proportional to height of liquid column

        It is true from above equation or by a simple example the force or pressure u feel when a small can placed on ur palm and a rather bigger can with taller water level (like a 200 ml bottle and a 5 L bottle is diffenent. This differnce is pressure differnce due to liquid column

2)directly proportional to density of liquid column

it is true u can see it from above equation itself

else just imagine pressure exerted by same amount of mercury is far more than water of same amount as due to density difffernceint

3)indenpendent of gravity

False

the above equation gives reason for it

or just think of space havent u seen water droplets floating in space

if u keep a 1L water bottle on ur hand u wont feel much weight as in Earth as there is no or negligible accelration due to gravity in space

So 1 and 2 true but 3 false

Answer 2

correct options are:

true

true

false