A soap bubble in vacuum has a radius $3\, cm$ and another soap bubble in vacuum has radius $4\, cm$. If two bubbles coalesce under isothermal condition. Then the radius of the new bubble will be .............. $\mathrm{cm}$
$7$
$5$
$4.5$
$2.3$
The diagram below shows a hydraulic lift. A force is applied at side $1$ and an output force is generated at side $2$ . Which of the following is true?
A given shaped glass tube having uniform cross-section is filled with water and is mounted on a rotatable shaft as shown in figure. If the tube is rotated with a constant angular velocity $\omega $ then
An engine pumps water through a hose pipe. Water passes through the pipe and leaves it with a velocity of $2\, m/s$. The mass per unit length of water in the pipe is $100\, kg/m$. ......... $W$ is the power of the engine .
The work done in blowing a soap bubble of radius $0.2\,m$, given that the surface tension of soap solution is $60\times10^{-3}\, N/M$ is
A manometer reads the pressure of a gas in an enclosure as shown in the figure.
The absolute and gauge pressure of the gas in $cm$ of mercury is
(Take atmospheric pressure $= 76\,cm$ of mercury)