Which of the following is not true for fertilisers?

The process of conversion of sugar into alcohol is called

The material similar to silk in appearance is

Materials which can be drawn into wires are called ductile. Which of the following is not a ductile material?

When coal burns in air

Shyam was cooking potato curry on a chulha. To his surprise. he observed that the copper vessel was getting blackened from outside. It may be due to

Which statement is incorrect about endangered species?

The table given below has certain terms and four blank spaces named A, B, C and D

From the options given below choose the correct combination of terms

Which of the following is not a viviparous animal?

Which endocrine gland is called 'Master gland'?

Some mustard oil is kept in the beaker. It will exert pressure

If we apply oil on door hinges, the friction will

An object is vibrating at 50 hertz. What is its time period?

Which one of the following solutions will not conduct electricity

An electroscope is a device which is used to find if an object is

As the angle between two plane mirrors is decreasing gradually, the number of images of an object placed between them

Which star is nearest to the Earth?

Which of these can cause acid rain ?

You must have seen the farmer plough seedlings of paddy into the field from a nursery. Give the name of this process

How do micro-organisms survive under adverse conditions?

What is plastic?

How can you say that metals have a property of sonorousness?

Can coal, petroleum and natural gas be created by human?

What are the characteristics of an ideal fuel?

Which animals are known as endangered animals?

Have you heard of a cell that behaves like a complete organism? Give its name

The change from tadpole to frog is given a particular term. What is it?

Roshni (11yrs Old) was worried about the changes in her body. How long do you think this period marked by Changes in the body will last?

While sieving grains, small pieces fall down. Which force pulls them down?

Explain fluid friction in brief.

Sound needs a medium for propagation. Explain it with an experiment

During the electrolysis of water, at which electrode, hydrogen gas is evolved?

What will you do on being struck by lightning?

Do we see all objects due to reflected light?

Give the name of the planet which is known to have largest number of natural satellites.

Microorganisms such as bacteria are also pollutants of water. In which category of pollutants, are they placed?

Give an appropriate term for each of the following.
(a) Chemical substance rich in particular nutrient.
(b) Plants of same kind grown in a field on large scale.
(c) Process of loosening and turning the soil.
(d) Rearing of fishes for its various products

Microorganisms survive under adverse conditions. How?

Write any three positive characteristics of plastic.

What happens when samples of metals and non-metals react with acids?

Look at the figure where petroleum and natural gas deposits are shown. Why do we find oil layer above water layer?

How does a match stick burn? Explain its process.

What will happen, if we go on cutting trees?

The number of cells are related to the size of animals. Explain how

Sumitra saw a bird protecting her eggs in a nest in the balcony of her house. After few days, she saw the little birds coming out of the eggs. She wondered if humans are also born this way. Her mother explained the difference.
(i) Is there a difference between birth of a baby, in case of a bird and a human?
(ii) Name few animals who lay eggs like the bird.
(iii) Identify the values displayed by Sumitra.

Define adolescence.

Briefly explain how do we experience force in our daily life.

Give examples to show that friction is both a friend and a foe.

Identify the part which vibrates to produce sound in the following instruments:
(i) Dholak
(ii) Sitar
(iii) Flute

The bulb glows when the electric current passes through it. Explain why.

In an electroscope, if a negatively charged body is brought in contact with the metal clip, the strips of the electroscope diverge. If now another charged object carrying equal amount of positive charge is brought in contact with the clip, what will happen?

Differentiate between regular and diffused reflection. Does diffused reflection mean the failure of the laws of reflection?

What is waxing and vanning of moon?

Name any two sources which cause air pollution due to Suspended Particulate Matter (SPM).

Discuss various systems of irrigation.

During biology class, teacher was telling about microbes and how they are useful to humans. Hearing this, Jasmine got confused as she knew the TB caused to her uncle is due to a microbe. She asked his teacher about it. The teacher appreciated her for question and explained the whole class.
(a) What are microbes?
(b) How are microbes helpful to humans?
(c) Name one microbe
(i) used in household products.
(ii) used in antibiotics.
(d) Mention two diseases other than TB caused by microbes.
(e) Identify the values shown by Jasmine.

Karan, a student of class VIII carelessly throw polybags here and there. Sometimes he throw the wrappers of chips, biscuits and other eatables on the road or in park or in his house. Karan's mother was very upset she told him not to throw things carelessly. She advised him to keep your home, school and public places clean. So, your younger brother will also learn the same thing. Karan followed her mother advice.
Read the following passage and answer the following questions.
(a) What is the harmful effects of throwing polybags or wrappers of food on public places.
(b) What are 4 R principle that are should follow to keep their environment clean?
(c) What values are shown by Karan?

Corrosion is a serious problem. Every year anenormous amount of money is spent to replace damaged iron. What steps can be taken to prevent this damage?

Why petrol is exhaustible natural resource whereas sunlight is not? Explain.

Forest fire produces a lot of air pollution. Write in brief about the reasons of forest fires.

What is poaching? How does poaching affect environment and humans?

What is a gene? What are its functions?

After observing figure above, answer the following.
(a) Read the following statements and label them in the figure.
(i) The part which produces female gametes.
(ii) The part where development of the baby takes place.
(iii) The part through which the developing embryo passes to reach the uterus.
(b) Explain the future development of the embryo that would take place after it gets embedded in the uterus.

Observe the chart and graph given in figure carefully and answer the following questions.

(a) Which of the line represents the height of boys?
(b) Which line represents the height of girls?
(c) What is the difference between the pattern of increase in the height of boys and girls?
(d) Is this pattern true for each individual?

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

In physics classroom a teacher told to his students that when a cricket player want to catch a ball then first he rub the hands. Thus, there is less chance of slipping the ball from hands. 
(a) Explain the reason of not slipping of ball from hand
(b) If the player makes his hands oily instead of rubbing them. Would he be able to catch the ball?
(c) Mention the type of teaching skills of teacher is being represented here?

How is sound produced and how is it transmitted and heard by us?

You are provided with a magnetic compass, an empty matchbox, a battery of two cells and connecting wires. Using these objects, how will you make a tester for testing an electric circuit? Draw the necessary circuit diagram and explain.

Across:
1. The graph used to record seismic waves.
2. The scale used to measure the magnitude of earthquake.
3. Sudden movement in the Earth plates.
4. A method of charging a neutral material.

There is a mistake in each of the following ray diagrams given as figure (a), (b), and (c). Make the necessary correction(s).

Figure shows comets without their tail. Show the tails of the comets at positions A, B, and C. In which position will the tail be longest?

How does air get polluted? Explain.