Pressure, Winds, Storms, and Cyclones — Quiz

Q1. Ravi finds it easier to drive an iron nail into a wooden plank using its pointed end rather than its head. The best reason is

• A. The pointed end has a smaller area, so the same force produces a higher pressure on the wood
• B. The pointed end is heavier than the head of the nail
• C. The wood is softer near the pointed end of the nail
• D. Iron becomes harder when hit from the pointed end

Q2. A vegetable vendor in Rampur places a round piece of cloth on her head before carrying a heavy basket. This is mainly because the cloth

• A. Increases the weight of the basket
• B. Reduces the temperature on her head
• C. Increases the area over which the weight acts, reducing pressure on her head
• D. Acts as a cushion against rain water

Q3. Overhead water tanks in colonies are placed at a height mainly because

• A. A greater height of the water column increases the water pressure in the taps below, giving a stronger stream
• B. Water at greater heights cools down faster
• C. Higher tanks store more water than lower tanks
• D. Higher tanks reduce the weight of the tank

Q4. The base of a dam is built much broader than its top mainly because

• A. It looks more attractive to visitors
• B. The horizontal water pressure near the bottom of the dam is much larger and the broad base helps it withstand this pressure
• C. More cement is available than steel
• D. It allows boats to be parked near the base

Q5. When Priya presses a rubber sucker firmly against a smooth flat surface, it sticks. To pull it off, the applied force must

• A. Be applied for a very long time, however small
• B. Be exactly equal to the weight of the sucker
• C. Be at least equal to the atmospheric pressure in pascals
• D. Be strong enough to overcome the pressure difference between outside and inside the sucker

Q6. The atmospheric air column over an area of 15 cm x 15 cm exerts a force of about 2250 N. The reason we are not crushed by this weight is that

• A. Our bones are stronger than steel
• B. The atmosphere does not really exert any force on living beings
• C. The pressure inside our bodies is equal to the atmospheric pressure and balances it
• D. Gravity does not act on the air column over us

Q7. If we could measure the speed of the air escaping in Activity 6.5, we would find that the speed of the air is higher when

• A. The pressure difference between the two balloons is higher
• B. The pressure difference between the two balloons is lower
• C. The two balloons are of the same colour
• D. Both balloons have exactly equal air pressure

Q8. During a storm with high-speed winds, it is generally safer to keep doors and windows of a house open because

• A. Cool air must enter the house
• B. It allows the pressure inside the house to become almost equal to that above the roof, reducing the risk of the roof being blown off
• C. Open windows make a pleasant sound during a storm
• D. Closed windows attract more lightning

Q9. The two important requirements for the formation of a thunderstorm are

• A. Cold dry air and gentle winds
• B. Snowfall and strong winds
• C. Polar air and dry winds
• D. Moisture and strong winds

Q10. Inside a thundercloud, after charge separation has taken place

• A. Positively charged heavy water droplets move to the top of the cloud
• B. Negatively charged ice particles occupy the top of the cloud
• C. Positively charged lighter ice particles move to the top of the cloud, while negatively charged heavier water droplets occupy the lower part
• D. All the positive and negative charges remain mixed and there is no charge separation

Q11. Local thunderstorms occurring in West Bengal, Bihar and Jharkhand before the arrival of the monsoon are known as

• A. Mango showers
• B. Bordoisila
• C. Kalboishakhi
• D. Western disturbances

Q12. Inside the eye of a cyclone, the weather is

• A. Calm, even though the surrounding region experiences strong winds and heavy rainfall
• B. Stormy and the most destructive part of the cyclone
• C. Marked by snowfall throughout the year
• D. Hotter than any other place on Earth

Q13. Once a cyclone moves from the ocean onto land, it gradually loses its strength because

• A. The land becomes much hotter than the ocean instantly
• B. The Earth stops rotating over land
• C. The source of moist air is cut off over land
• D. Lightning increases sharply over land

Q14. In India, the official organisation that constantly monitors cyclones and thunderstorms and issues warnings is the

• A. Indian Space Research Organisation (ISRO)
• B. National Disaster Response Force (NDRF)
• C. India Meteorological Department (IMD)
• D. Geological Survey of India (GSI)

Q15. During a thunderstorm with frequent lightning, the safest action on an open ground is to

• A. Find a low-lying open area and crouch down, minimising contact with the ground
• B. Stand under the tallest tree available for shelter
• C. Lie flat on the ground with arms outstretched
• D. Open an umbrella with a metallic rod for protection