Evaporation of a material takes place __________

Which of the following properties is not characteristic of colloidal particles?

One atomic mass unit is equal to weight of

The nucleus of an atom is approximately

Which cell organelle is involved in the formation of lysosomes?

Which of the following is the fat-storing tissue?

The five kingdom classification is based on complexity of

An object moves with a uniform velocity of 9.8 m/s its acceleration is

When an object undergoes acceleration

10 kg wt is equal to

Two particles of masses 1 g and 4 g have equal momentum.What is the ratio between their kinetic energies?

Hz is the unit of

Which one of the following is not the common disease caused by viruses?

The life supporting zone of the earth where the atmosphere the hydrosphere and the lithosphere interact is known as

Which variety of honey bee have high honey collection capacity?

In what ways air can be considered as matter?

State two properties of carbon which are excepted from its classification as a non-metal.

Write down the formulae of
(a) sodium carbonate
(b) ammonium chloride
(c) Zinc oxide
(d) aluminium hydroxide

An atom of an element has full K and L shell has 5 electrons in its M-shell.What is its atomic number?

Differentiate between prokaryotic cell and eukaryotic cell.

List four elements of phloem. Which one of them is most important and why?

Bittu and Chinka live in a village. They planned to go to nearby pond to catch fish. They took a small net to trap fishes. Whenever any unwanted animal, such as small tortoise, very small fish, small snails, etc. and aquatic plants, like Hydrila, come in the net, Chinka used to put them back in the pond.
Answer the following questions above information:
(a) What would have happened, had they killed those animals and thrown the plants as wastes?
(b) Give one reason to justify that Chinka's action is environment friendly.
(c) How can you contribute in the preservation of flora and fauna around us?

What are vector quantities? Give examples

A car of mass 1000 kg moving with a velocity of 45 km / h collides with a tree and comes to a stop in 5s. What will be the force exerted by the car on the tree?

The dimensions of wooden block are 2 m x 0.25 m x 0.10 m. If relative density of wood is 0.6, calculate mass of the block in kg. Density of water =10³ kg/m³

A person is holding a pitcher full of water over his head for twenty minutes and gets tried.Has he done some work or not?Justify your answer.

What are mechanical or elastic waves? Give examples.

Give two examples of each of communicable and non-communicable diseases.

List water pollutants.

In what way manure help in soil fertility?

What do you mean by diffusion? Explain giving an example.

Write characteristics of compounds.

How many grames of Na will have the same number of atoms as in 6 grames of Mg?(Atomic mass Na=23.0u, Mg=24.0u)

What are the uses of isotopes?

Differentiate between Prokaryotic cell Eukaryotic cell.

Differentiate between bone and cartilage.

What are the differences between animals belonging to the Aves group and those in the mammalia group?

Deduce the relation:s = ut + \(\frac { 1 }{ 2 } at^{ 2 }\) where the symbols used have their usual meanings

A car of mass 1000 kg moving with a velocity of 40 km/h collides with a tree and comes to stop in 5 s. Calculate the force exerted by the car on the tree.

A boat of mass 50 kg is floating in the river with \(\frac{1}{2}\) of its volume inside the water. Calculate the buoyant force acting on the boat. (Take, g = 10 ms^-2)

(a) What is the gravitational potential energy?
(b) Derive an expression for the gravitational potential energy of an object at height.

Define the term 'tone'.A person id listening to a sound of 500Hz sitting at a distance of 450m from the source of the sound.What is the time interval between successive compression reaching his ears from the source?

List the measure for preventing infectious diseases.

What are the sources of water pollution?

Write different crop combinations groups used in crop rotation depending upon one-year to three-year duration.

Give reasons:
(i) Solid carbon dioxide (dry ice) is stored under high pressure.
(ii) at many places, especially in rural areas, people often sprinkle water on the ground in front of their homes during hot summer evenings.

List the various types of homogeneous and heterogeneous mixtures with examples.

How were the names of elements derived?

What the help of Table 4.1, find out the mass number of oxygen and sulphur atom.

Water forms two-thirds of the weight of the body. Body cells contain about 60% to 70% of water.All life processes carried out in a cell require water medium.It is essential to well being, deprivation or loss of water, as in case of diaohrrea, dysentry, vomiting etc. is more immediately serious than of any other article in diet.On the basis of above information answer the following questions:
(i) What first aid you will provide to a patient who has lost sufficient water from the body cells due to loose motions?
(ii) How would you prepare the solution to hydrate the body cells of the patient?
(iii) What would you do for the community with this information?

What is the specific function of the cardiac muscle?

What is the advantage of using scientific names instead of common or popular names?

What is non-uniform motion? Give some examples.

State Newton's first law of motion. Explain it with the help of suitable examples.

State any three differences between mass and weight.

A person holds a bundle of hay over his head for 30 minutes and gets tried.Has he done some work or not?Justify your answer.

Define the terms time period and frequency of an oscillating body. Give their units and write the relation between them.

Give cause and remedy of
(a) Hepatitis (b) AIDS (C) Malaria

Is it necessary to replenish forests?

Define crop rotation. How are crops selected for crop rotation?

(a) What is matter? Write two properties of solids and two properties of liquids.
(b) Ramesh took two beakers A and B containing hot water and cold water respectively. In each beaker he dropped a crystal of copper sulphate. He kept the beakers undisturbed. After sometime what did he observe? Why? 

A silver ornament of mass m gram is polished with gold equivalent to 1% of the mass of silver. Compute the ratio of the number of atoms of gold and silver in the ornament.

(i) One mole of carbon atom weighs 12 g.Find the mass in grams of one atom of carbon (Given C = 12u, No = 6.022 x 10²³ per mole)
(ii) Calculate the mass of the following:
(a) 0.5 mole of N2 gas
(b) 0.2 mole of O-atoms
(c) 4 moles of aluminium atom
[Given, N = 14 u, 0 = 16 u, Al = 27 u,
Avogadro's number = 6.022 x 10²³ per mole ]

Describe the role played by the lysosomes in the cell. Why are these termed as suicidal bags? How do they perform their function?

The following table gives the data about motion of a car?

Plot the Distance-time graph:
(i) Find the speed of the car between 12.00 hours and 12.30 hours
(ii) What is the average speed of the car?
(iii) Is the car's motion an example of uniform motion? Justify.

(i) Write the formula to find the magnitude of gravitational force between the earth and an object on the earth's surface.
(ii) Derive how does the value of gravitational force F between two objects change when
(a) distance between them is reduced to half and
(b) mass of an object is increased four times

(a) Define average power.Calculate the total energy consumed in the month of November in a household in which four devices of power 500 W each are used daily for 10 hours.
(b) What should be the mass of a bullet if its speed is 100 m/s and it possesses a kinetic energy of 0.1 kilojoule?