WIND STORMS AND CYCLONES

IDENTIFY THE DEVICE AND ITS USE

• ANEMOMETER, TO FIND WIND DIRECTION

• BAROMETER,TO FIND WIND SPEED

• ANEMOMETER TO FIND WIND SPEED

• NONE OF THESE

INCREASED WIND SPEED IS ACCOMPANIED BY

• NO CHANGE IN TEMPERATURE

• NO CHANGE IN PRESSURE

• REDUCED AIR PRESSURE

• INCREASED AIR PRESSURE

WHAT HAPPENS TO AIR ON HEATING?

• IT STOPS MOVING

• IT EXPANDS AND BECOMES LIGHTER

• IT CONTRACTS AND BECOME LIGHTER

• IT EXPANDS AND BECOME HEAVIER

WIND IS

• MOVING AIR

• STILL AIR

• HUMID AIR

• ALL OF THESE

WHEN WE FILL AIR IN BICYCLE TUBE IT INFLATES . BUT IF WE CONTINUE TO DO SO,IT WILL BURST AS THE AIR IS EXERTING (a)   ON THE WALLS OF THE TUBE.

CONVECTION IN AIR TAKES PLACE BECAUSE

• WARM AIR AND COLD AIR HAVE SAME DENSITIES

• COLD AIR IS DENSER THAN WARM AIR

• WARM AIR IS MORE DENSE THAN COLD AIR

• NONE OF THESE

What causes winds?

• DIFFERENCE IN AIR PRESUURE

• EQUILIBRIUM OF AIR PRESSURE

a child blowing air with a straw near the opening of another straw which has its other end in a soft drink bottle. It was observed that the level of the soft drink in the straw rises up as soon as air is blown over its open end. Which one of the following best explains the reason for rise in level of the drink?

• Blowing of air increases the pressure on the surface of soft drink in the bottle.

• The straw of the soft drink bottle collapses when air is blown over its open end

• Blowing of air warms up the air inside the straw.

• Blowing of air decreases pressure over the opening of the straw.

A curtain is hanging at the entrance of a room and a long corridor runs parallel to the curtain. If a strong wind blows along the corridor, the curtain will

• get pushed inside the room.

• get pushed outside the room.

• get collected towards one end/swirled.

• remain unaffected.

THE PAPER BAG KEPT ABOVE THE CANDLE FLAME IN THE BALANCE WOULD

• RISE UP

• DESCEND DOWN

• BE AT THE SAME LEVEL OF THE OTHER BAG

• NONE OF THESE