Weeds are the

PET is a

Two charged objects are brought close to each other. Choose the most appropriate statement from the following options

Which of the following cannot be charged easily by friction?

The change in converging power of an eye lensis caused by the action of

Which of the following statements is correct regarding rods and cones in the human eye?

Phases of the moon occur because

Our galaxy is known as

The Kyoto protocol is associated with one of the following.

Boojho wishes to contribute in reducing air pollution. Which vehicle should he use for going to school?

How is rayon formed?

An electric spark on a huge scale.

Who invented the system of reading for blind people?

Brightest star in the sky.

Write the composition of air by volume.

Boojho wants to know how many tools are used in cutting of crops?

Jute fibres are obtained from which part of the jute plant?

What are seismic waves?

What is earthing? What is its importance?

The angle between incident ray and reflected ray is 60°. What is the value of angle of incidence?

Lack of which vitamin causes troubles in our eyes? Name some food stuff to cure this problem.

If I am 13 years old, how many times have I gone around the sun?

What is a meteor?

A part of radiation is absorbed by CO₂, Write the this part.

Explain the Ganga Action Plan in short.

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

Plastic is used for making a large variety of articles of daily use and these articles are very attractive. But it is advised to avoid the use of plastic as far as possible. Why?

Describe with the help of a diagram an instrument which can be used to detect a charged body.

How are industries responsible for the water pollution?

How can water be made safe for drinking? Explain in brief.

A group of students conducted an activity where they took three glasses A, B and C with same amount of soil and planted same sized seedlings. They added cow dung manure in glass A, little urea in glass B and nothing in C. Based on the observations after a week, answer the following:
(a) In which glass, will you find seedling?
(b) Seedlings of which glass shows maximum growth?
(c) Give the inference of the activity.
(d) Name the natural substance obtained from residues of plants.
(e) Mention the role of soil.

Despite being very useful, it is advised to restrict the use of plastic. Why is it so? Can you suggest some methods to limit its consumption?

Explain why it is safer to use a wireless telephone instead of a land line telephone during lightning.

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.

Last Sunday morning, Pooja decided to see some bollywood movie along with her college friends. When they all entered in the cinema hall, then Pooja found some difficulty in observing the things around her but after few minutes, she got comfortable with the surroundings and she took her seat and spent 3 hrs approximately in seeing the movie. But when all of them made their exit from the all, then Pooja again left some discomfort in her eyes. At the same time, Pooja wore her goggles in order to protect herself from bright sunlight.
(a) Explain the brief that what happens to Pooja's eyes before and after seeing the movie in cinema hall.
(b) State the values showed by Pooja here.

Write down the names of parts of the eye in the blank spaces shown in fig. below.

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?

Suppose the distance between the earth and sun becomes half of its present distance. What is likely to happen to life?

Read the paragraph and answer the questions following it.
Water is essential for life. Without water there would be no life. We usually take water as granted for its purity, but we must ensure the quality-of water. Pollution of water originates from human activities. Through different paths, pollution reaches to groundwater. Easily identified source or place of pollution is called as point source, e.g. municipal and industrial discharge pipes, where pollutants enter the water source. Non-point sources of pollution are those where a source of pollution cannot be easily identified, e.g. agricultural run-off, acid rain, etc.
(a) How do you classify the various sources of water pollution?
(b) What are the point sources of water pollution?
(c) Name any two non-point sources of water pollution?

Why is it advised that industries should switch over to cleaner fuels such as CNG and LPG in the TajMahal Zone in Agra ?