Water flows through a horizontal pipe with a cross-sectional area of $10 \, cm^2$ at a speed of $5 \, m/s$. The water then flows into a narrower section of the pipe with an area of $5 \, cm^2$. Ignoring viscosity, what is the pressure difference between the wider and narrower sections?

A body floats in water with 40% of its volume outside water. When the same body floats in an oil, 60% of its volume remains outside oil. The relative density of oil is

A balloon of volume $1500{{\rm{m}}^3}$ and weighing 1650 kg with all its equipment is filled with He (density$0.2{\rm{kg}}{{\rm{m}}^{ - 3}}$. If the density of air be $1.3{\rm{kg}}{{\rm{m}}^{ - 3}}$, the pull on the rope tied to the balloon will be

Two solid pieces, one of steel and the other of aluminum when immersed completely in water have equal weights. When the solid pieces are weighed in air

An ice block floats in a liquid whose density is less than water. A part of block is outside the liquid. When whole of ice has melted, the liquid level will

To what height should a cylindrical vessel be filled with a homogeneous liquid to make the force with which the liquid presses on the sides of the vessel equal to the force exerted by the liquid on the bottom of the vessel. If should be

Two pieces of metal when immersed in a liquid have equal upthrust on them; then

Density of ice is $\rho$ and that of water is $\sigma$. What will be the decrease in volume when a mass $M$ of ice melts

An iceberg is floating in water. The density of ice in the iceberg is $917{\rm{kg}}{{\rm{m}}^{ - 3}}$ and the density of water is $1024{\rm{kg}}{{\rm{m}}^{ - 3}}$

A venturi-meter is used to measure the flow speed of a fluid in a pipe. Its operation is based on which principle?

A horizontal pipe of non-uniform cross-section has water flowing through it. At a point where the cross-sectional area is $20 \, cm^2$, the water velocity is $2 \, m/s$. What is the velocity at a point where the area is $10 \, cm^2$?