The term used for the process of separation of grains from chaff is

1

(a)

sieving

(b)

winnowing

(c)

threshing

(d)

hand picking

Metals are generally hard. Which of the following metals is an exception and can be cut with a knife?

1

(a)

Iron

(b)

Sodium

(c)

Gold

(d)

Magnesium

Exhaustible natural resources are

1

(a)

unlimited in quantity

(b)

not dependent on nature

(c)

limited in quantity

(d)

not exhausted by human activities

The most important function of cell membrane is that it :

1

(a)

controls the entry and exit of materials from cells

(b)

controls only the entry of materials into cells

(c)

controls only the exit of materials from cells

(d)

allows entry and exit of materials without any control

Which among the following hormones controls calcium metabolism in our body?

1

(a)

Insulin

(b)

parathorme

(c)

Thyroxine

(d)

Adrenaline

In figure, two boys A and B are shown applying force on a block. If the block moves towards the right, which one of the following statements is correct?

1

(a)

Magnitude of force applied by A is greater than that of B

(b)

Magnitude of force applied by A is smaller than that of B

(c)

Net force on the block is towards A

(d)

Magnitudeof force applied by A isequalto that of B

A characteristic of sound that depends on the amplitude is

1

(a)

pitch

(b)

speed

(c)

quality

(d)

loudness

The movement of the earth's plates causes

1

(a)

cyclones

(b)

lightning

(c)

earthquake

(d)

thunderstorms

The change in seasons on the earth occurs because

1

(a)

the distance between the earth and the sun is not constant

(b)

the axis of rotation of the earth is parellel to the plane of its orbit

(c)

the axis of rotation of the Earth is perpendicular to the plane of its orbit

(d)

the axis of rotation of the Earth is tilted with respect to the plane of its orbit

Air is a mixture of various gases. One of the gas is 21% part of the air and is essential for the survival of human beings. This gas is

1

(a)

nitrogen

(b)

oxygen

(c)

ozone

(d)

argon

A most common weedicide is..........

1

(a)

2,4-D

Identify the organism given below. Where does it reproduce?

1

(a)

Virus. It reproduces in the host cell.

Static friction is ________ than the sliding friction.

1

(a)

greater

Nitrogen fixation occurs during ___________.

1

(a)

lightning

_________ is a group of stars arranged in a definite pattern.

1

(a)

Constellation

PVC is thermosetting plastic.

1

(a) True

(b) False

External fertilisation can occur both in water and on land.

1

(a) True

(b) False

Ball bearing is a device which converts static friction into sliding friction.

1

(a) True

(b) False

Sound makes eardrum vibrate.

1

(a) False

(b) True

Potable water is translucent.

1

(a) True

(b) False

What is the process of loosening and turning of the soil called?

1

(a)

Tilling or ploughing

What is the versatility about melamine?

1

(a)

It resists fire and can tolerate heat better than plastic.

Name the biosphere reserve where the plants and animals are found similar to the upper Himalayan peaks.

1

(a)

Pachmarhi Biosphere Reserve.

Name a solution which should be added to make onion peel slide.

1

(a)

Methylene blue

What do you mean by metamorphosis?

1

(a)

The change from larva to an adult is called metamorphosis

How can fluid friction be minimized?

1

(a)

Changing the shape of machine

What is vibration?

1

(a)

The to and fro motion of an object is called vibration.

A scale to check the power of an earthquake.

1

(a)

Richter scale

Where is image formed in human eye?

1

(a)

Image is formed on retina in human eye.

Name few alternative fuels to reduce pollution

1

(a)

CNG and LPG

If a person is a pisciculturist, what does he do?

2

(a)

If a metal coin is dropped on hard floor, it produces a ringing sound. What is this property of metals known as?

2

(a)

Out of kerosene oil or wood, which has higher ignition temperature?

2

(a)

Mention the name of the two states of motion:

2

(a)

The aluminium strips in an electroscope as shown in figure are replaced by plastic strips and a charged body is brought in contact with the metal clip. What will happen?

2

(a)

Name the disease-causing microorganism of the following
(a) swine flu
(b) rust of wheat
(c) anthrax

2

(a)

List various constituents of petroleum and their uses.

2

(a)

What is the term used for chemical secretions of endocrine glands responsible for changes taking place in the body?

2

(a)

While travelling on a rickshaw, you might have experienced that if the seat cover is very smooth, you tend to slip when brakes are applied suddenly. Explain.

2

(a)

A poisonous gas P is produced by incomplete combustion of fuels such as coal. This gas interferes with Q of blood and reduces its capacity to carry gas R. Instead, it combines itself with Q forming S. What are P, Q, R, S?

2

(a)

1. Explain the use of Bacteria, Fungi and Algae.

   5

   (a)

2. The substance A is a fossil fuel. It occurs deep below the earth's crust in certain areas. Another fossil fuel B is found above the substance A. When A is subjected to a process C, a number of different products (fractions) are collected at different temperature ranges which have different uses. A special grade of product D obtained in this process is used as aviation fuel in jet aeroplanes. The product D is also used in stoves, lamps, etc
   Now give the answer of the following questions.
   (a) What are the substances, A and B?
   (b) Write the physical states of substances A and B.
   (c) What is the process C called?
   (d) Name the product D.

   5

   (a)

1. Rohit while gardening observed many beautiful flowering plants. He got attracted by the brightly coloured flowers and their beautiful appearance. He was curious to know about the variation of colours in flowers and asked her biology teacher about it. Teacher told her about the plastids found in plant cells.
   (a) A particular plastid is responsible for the variation in colours of flowers. Which is it?
   (b) Name the plastids known as kitchen of the cell.
   (c) Are all plastids coloured?
   (d) Will we be able to observe plastid in an animal cell?
   (e) Identify values shown by Rohit.

   5

   (a)

2. What are contact and non-contact forces? Explain briefly with suitable examples.

   5

   (a)

1. Mention the property of vibrations which determine the pitch of the sound. Briefly explain along with some examples.

   5

   (a)

2. Water is one of our most precious commodities and no life can survive without it. It has been predicted that water scarcity will become the subjects of 'Wars' in the near future. Write any two ways in which water is getting polluted. Write any two measures to stop water pollution at your level.

   5

   (a)