Science

Q. Explain the differences between regular and irregular reflection light.

Q.

Why is it important to remove weeds from the cultivated field in early stage of the crop?

1. Weeds are poisonous to crops.

2. Weeds are parasitic on the crops and hence will destroy the crop plant completely.

3. Weeds resemble the crop plants and hence it will be difficult to identify between the crop and weed.

4. Weeds compete with the crop plants for all essential requirements, thus reducing crop yield.

Q.

Who discovered the nucleus?

1. Purkinje

2. M. Schleiden

3. Robert Hooke

4. Robert Brown

Q. The imaginary line that divides the Earth into the Northern and Southern Hemisphere is called the __.

1. 
   prime meridian
2. 
   equator
3. 
   vertical line
4. 
   horizontal line

Q.

Where does the Moon rise and set?

1. The moon rises in the north and sets in the south.

2. The moon rises in the west and sets in the east.

3. The moon rises in the south and sets in the north.

4. The moon rises in the east and sets in the west.

Q.

What is the advantage of turning and loosening of soil before sowing?

1. This brings the nutrient-rich soil to the top so that plants can use the nutrients present in the lower layer.

2. The nutrients of the top layers can get a chance to go below to facilitate the growth of burrowing animals

3. The nutrients present in the soil can get evaporated by this process

4. The colour of the soil particles can be maintained by this process.

Q.

Where are the diamond mines in India located?

Q.

Which of the following is not a fossil fuel?

1. Natural gas

2. Sunlight

3. Petroleum

4. Coal

Q.

Which of the following reaction will not occur?

1. ZnSO4+ Cu → CuSO4+ Zn

2. CuSO4+Fe → FeSO4+ Cu

3. Cu + AgNO3 →CuNO3+ Ag

4. FeSO4+Zn → ZnSO4+ Fe

Q.

A copper coin is immersed in a solution of silver nitrate for some time. What will happen to the coin and colour of the solution?

1. Copper coin will dissolve in the solution. The colour of the solution will not change.

2. There will be no change in copper coin and in the colour of solution.

3. There will be no change in copper coin. The colour of the solution will change from colourless to blue.

4. Copper coin will dissolve in the solution. The colour of the solution will change from colourless to blue.

Q.

Which hormone is responsible for the development of secondary sexual characters in females?

1. Estrogen

2. Progesterone

3. Testosterone

4. Insulin

Q. How is sound produced in a human larynx and a loudspeaker?

Q.

Sodium catches fire when it comes in contact with water because:

1. The reaction of sodium metal with water is highly heat producing due to which the NaOH formed during the reaction catches fire and burns causing little explosions.

2. The reaction of sodium metal with water is highly heat producing due to which the oxygen gas formed during the reaction catches fire and burns causing little explosions

3. Sodium is an explosive metal.

4. The reaction of sodium metal with water is highly heat producing due to which the hydrogen gas formed during the reaction catches fire and burns causing little explosions.

Q. Answer the following.
a. Thermocol is produced from which matterial ?

b. Write uses of PVC.

c. Write the natural or manmade row material of the following items.
Matteress, beaker, bangle, chair, gunny bag, knife, pen

d. Which are the main ingredients of glass ?

​e. How the plastic is produced ?

Q. Write 10 lines on the usefulness of microorganisms in our lives.

Q. Write brief answers.
a. Describe a clinical thermometer. How does it differ from the thermometer used in laboratory?

b. What is the difference between heat and temperature ? what are their units.

c. Explain the construction of a calorimeter. Draw the necessary figure.

d. Explain why rails have gaps at specific distances.

e. Explain with the help of formulae the expansion coefficients of liquid and gas.

Q. Explain the importance.
A. Balanced diet.
B. Physical exercise / Yogasanas.

Q. Distinguish between
a. Manmade material and natural material
b. Thermoplastic and thermosetting plastic.

Q. Why do we have seasons on Earth?

1. 
   The Earth is tilted on its axis.
2. 
   Because the Earth revolves around the Sun.
3. 
   The Sun is tilted on its axis.
4. 
   The distance between Earth and Sun changes.

Q.

What is the function of the neutrons in the nucleus?

Q. Describe the construction, working and usefulness of a dry cell, with the help of a diagram.

Q.

What happens when zinc is added to a solution of iron sulphate?

1. Grey precipitate will be formed.

2. Zinc will not displace iron from its solution.

3. Green precipitate will be formed.

4. Green solution is obtained; no precipitate is formed.

Q.

Phosphorus is stored in water because:

1. It is a reactive non metal and it reacts with moisture present in air.

2. It is a reactive metal and it catches fire when exposed to air. To prevent this, it is stored in water.

3. It is a metal and it does not react with water.

4. It is very reactive non-metal which does not react with water. It immediately catches fire when exposed to air. To prevent this, it is stored in water.

Q.

Which of the following metal can displace zinc from its solution of zinc sulphate?

1. Zinc

2. Magnesium

3. Copper

4. Silver

Q.

How does carbon dioxide cause global warming?

Q.

What happens when iron fillings are added to copper sulphate solution?

1. Light deep blue solution of iron sulphate is obtained.

2. There will be no change in the colour of the copper sulphate solution.

3. Light green solution of iron sulphate is obtained.

4. A grey coating of copper metal is formed on the surface of iron nail.

Q.

What is the importance of the Pole Star?

Q.

The first law of reflection states that :

1. The angle of incidence is always equal to the angle of reflection.

2. The angle of incidence is always equal to the angle of reflection only when the mirror is kept at an angle of 45^o.

3. The angle of incidence is sometimes equal to the angle of reflection.

4. The incident ray, the reflected and the normal at the point of incidence all lie in the same plane.

Q.

If the forces acting upon an object are balanced, then the object:

1. Must not move

2. Must move with constant velocity

3. Must not accelerate

4. Either A or B depending on the situation

Q.

Draw a labelled diagram showing the process of distillation.