Upper Sec Convection current

What is convection?

• Transfer of heat through a fluid by movement of the fluid

• Transfer of heat through a solid by movement of the solid

• Transfer of heat through a vacuum by movement of particles

• Transfer of heat through a gas by movement of the gas

What is a fluid?

• A liquid or a gas

• A liquid, gas, or solid

• A solid or a gas

• A liquid or a solid

Why can't convection occur in a solid?

• Solid particles are fixed and cannot move freely

• Solid particles are too dense to move

• Solid particles are constantly moving

• Solid particles are too light to move

Why can't convection occur in a vacuum?

• There are no particles in a vacuum

• Particles in a vacuum are too dense to move

• Particles in a vacuum are too light to move

• Particles in a vacuum are constantly moving

What happens to the water at the bottom in a convection process in a heated swimming pool?

• It gets cooled and sinks to the bottom

• It gets heated, expands, become less dense and rises

• It remains at the same temperature

• It evaporates into gas

What happens to the air at the top in a convection process in a hot air balloon?

• It condenses into liquid

• It remains at the same temperature

• It gets cooled, becomes denser and sinks to the bottom

• It gets heated, expands, and rises

Why is convection in gas faster than convection in liquid?

• Gas expands more than liquid for the same heat applied

• Gas contracts less than liquid for the same heat applied

• Gas contracts more than liquid for the same heat applied

• Gas expands less than liquid for the same heat applied

What is an everyday application of convection related to a heating coil in a kettle?

• Evaporating the water into gas

• Heating the water at the top

• Setting up a convection current in the water

• Cooling the water at the bottom

What is an everyday application of convection related to a freezer placed at the top of a fridge?

• Condensing the air into liquid

• Setting up a convection current in the air

• Heating the air at the top

• Cooling the air at the bottom

A radiator is placed near the ground of a room. Draw the convection current in the room.