Air

Q. What are the pros and cons of using an alcohol thermometer?

Q.

Which of the statements given below is correct?

1. In winter the winds flow from the land to the ocean.

2. In summer the winds flow from the land towards the ocean.

3. A cyclone is formed by a very high-pressure system with very high-speed winds revolving around it.

4. The coastline of India is not vulnerable to cyclones.

Q. In the day time, when we go to the sea the air blows towards us and does not go towards the sea. Explain.

Q.

What is the power generated in a windmill?

Q. Atmospheric pressure decreases with ___ in temperature.

Q.

A mirror is an example of___ object.

1. Opaque

2. Transparent

3. Translucent

4. Reflecting and opaque

Q. Hot air is lighter (less dense) than cold air.

1. True
2. False

Q.

The following are the elements of weather except __________.

1. Temperature

2. Soil

3. Rain

4. Humidity

Q. Wind flows from a high-pressure region to low pressure region.

1. True
2. False

Q.

From the following objects, list out the transparent, translucent and opaque bodies.

$\begin{array}{cccc}& OBJECTS& & TYPEOFMATERIAL\\ 1& Plywoodsheet& a& Transparent\\ 2& Tracingpaper& b& Translucent\\ 3& Glasssheet& c& Opaque\end{array}$

1. 1-b; 2-c; 3-a

2. 1-a; 2-b; 3-c

3. 1-c; 2-b; 3-a

4. 1-a; 2-c; 3-b

Q. Pick the object that only partially allows light to pass through it.

1. Chocolate bar
2. Glass bowl
3. Pencil
4. Butter paper

Q. Choose the properties of alcohol.

1. It is a good conductor of electricity
2. It can be used to record only very low temperatures
3. It can be coloured brightly and hence is easily visible
4. Its expansion increases with increase in temperature

Q. A magician fills up one-third of a glass with water. He places a card over the mouth of the glass and inverts it. The water doesn't fall. Pick the correct explanation for this phenomenon

1. air pressure outside the glass is more than the weight of the water in the glass.
2. air pressure outside the glass is less than the weight of the water in the glass.
3. air pressure inside the glass is more than the weight of the water in the glass.
4. air pressure outside the glass is less than the weight of the water in the glass.

Q.

Transparent medium doesnt cast a shadow

So why does water in a glass, both being transparent, cast a shadow

Q.

The power generated in a windmill:

1. Is more in rainy season since damp air would mean more air mass hitting the blades

2. Depends on the height of the tower

3. Depends on wind velocity

4. Can be increased by planting tall trees close to the tower