Large volume of compressed natural gas (CNG) is available in small cylinders to us due to its property of __________

Take the statement which is not correct:

Which one of the following elements gives polyatomic molecules?

The size of an atom is decided by:

Which cell organelle is involved in the formation of lysosomes?

Muscles are joined to the bones by

Five kingdom classification, was proposed by

The distance travelled by a freely falling body is proportional to the

A force of 15 N acts separately on two bodies of masses 3 kg and 5 kg. The ratio of the accelerations produced in the two cases will be

The force of gravitation between two bodies does not depend on

If the speed of a motor car increases by six times, its kinetic energy will increase by

Sound waves having the following frequency audible by a human being are:

The protozoan organism that causes kalaazar is

Ozone hole was first observed over

Which variety of honey bee have high honey collection capacity?

For any substance why does temperature remain constant during change of state?

Classify each of the following as homogeneous or heterogeneous mixtures
soda water, wood, air, soil, vinegar, filtered tea.

A gas jar contains 1.7 g of ammonia gas.Calculate the following:
(i) Molar mass of ammonia
(ii) How many moles of ammonia are present in the gas jar?
(iii) How many molecules of ammonia are present in the sample?

The following data represents the distribution of electron, protons and neutrons in atoms of four elements A, B, C and D.

What is lacking in a virus which makes it depending on a living cell to multiply?

How are simple tissues different from complex tissues in plants?

Name three groups which are placed under cryptogamae. State and explain two characteristics, which are exhibited by each category of these plant bodies.

A moving train is brought to treat within 20 s by applying brakes Find initial velocity if the retardation due to brakes is 1.5 \(m/s^{ 2 }\) .

Define inertia of direction. Give some examples of inertia of direction.

(a) Observe the elongation of the rubber string due to the weight of a piece of stone suspended from it in air, (b) The elongation decreases as the stone is immersed in water

A pair of bullocks exerts a force of 140 N on a plough.The field being ploughed is 15 m long.How much work is done in ploughing the length of the field?

Give some examples of waves which are combination of both transverse and longitudinal wave motion.

A baby is not able to tell her/his caretaker that she/ he is sick.What would help us to find out
(a) that the baby is sick
(b) What the sickness is?

Differentiate between nitrification and denitrification.

List culture fisheries in sea water.

Give reasons:
(a) Salt and sugar when kept in different jars take the shape of the jars, yet they are classified as solids.
(b) Solids have negligible compressibility yet sponge can be compressed.
(c) Gases exert pressure on the walls of the container.

(a) name the separation techniques which you will apply the separation of the following mixtures:
(i) Small piece of metal in the engine oil of a car
(ii) Fine mud particles suspended in water 
(iii) Oil from water.
(iv) Sodium chloride from its solution in water.
(v) Camphor from salt.
(vi) Wheat grains from husk.
(b) Classify the following as a chemical or physical change:
(i) Water boils to form steam.
(ii) Burning of paper.
(iii) An almirah gets rusted.
(iv) Making a fruit salad with raw fruits.

Calculate the number of molecules of glucose present in its 90 grams.
(molecular mass of glucose is 180 u)(6.02 x 10²³ mol^-1)

State the three rules that are followed for determining the number of electrons in different energy levels or shells in an atom.

(a) What would happen to the life of a cell there was no Golgi apparatus?

(b) Which cell organelle detoxifies poisons and drugs in the liver of vertebrates?

What are the components of phloem? Briefly describe its role in plants.

What is the difference between Bryophyta and Pteridophyta?

Establish the relation \(v^{ 2 }-u^{ 2 }=2as\) , where 'u' is the initial velocity, 'v' the final velocity 'a' the uniform acceleration and 's' is the distance covered by the body. 

The second law of motion is often seen in action in our everyday life. You must have noticed that while catching a fast moving cricket ball, a fielder in the ground gradually pulls his hands backwards with the moving ball. In doing so, the fielder increases the time during which the high velocity of the moving ball decreases to zero. Thus, the acceleration of the ball is also reduced. If the ball is stopped suddenly then its high velocity decreases to zero in a very short interval of time. Thus the rate of change of momentum of the ball will be large. Therefore, a large force would have to be applied for holding the catch that may hurt the palm of the fielder.
(a) State Newton second law of motion.
(b) State relation between force of momentum.
(c) What is the SI unit of force?
(d) Why we are hurt less when we jump on a muddy floor in comparison to a hard floor?

The earth is not a perfect sphere. As the radius of the radius of the earth increases from the poles to the equator, the value of g becomes greater at the poles than at the equator. As one goes above the earth's surface, the value of g decreases. If one goes deep inside the earth, then also the value of g decreases. In fact, the value of g becomes zero at the centre of the earth. Moreover, due to the rotation of the earth, the weight of a body is maximum at the poles and minimum at the equator.
(i) Name the factors on which the value of 'g' depends.
(ii) What is the effect of altitude on acceleration due to gravity?
(iii) What is the effect of rotation of the earth on the acceleration due to gravity?

If the mass of a car is 1500 kg, what work is to be done to increase the velocity of the car from 18 km/h to 36 km/h?

Let us consider some examples of motion : (a) Motion of a swing,(b) Motion of the hands of a watch,(c) Motion of the earth around the sun, All these motions repeat after some fixed interval of time. Such a motion is called periodic motion.The  motion of the swing is such that the swing moves to and from about its mean position Such a motion is called oscillatory or vibratory motion.
Answer the following questions based on the above information:
(a) Define periodic motion
(b) Define oscillatory motion
(c) Can a motion be periodic but not oscillatory?
(d) Motion of the earth is periodic but not oscillatory .Justify.

Given an example where tissue-specificity of the infection leads to very general seeming effects.

Why is replenishment of forests necessary?

(a) What is composite fish culture system?
(b) Mention one merit and one demerit of this system.

What is pressure?What is its unit?On what factor does the pressure of a gas depend?

(a)Compare true solution, suspension and colloidal in terms of:
(i) filterability 
(ii) stability
(b) List two factors which bring about a change in the state of matters say, gas to liquid.

How were the names of elements derived?

Give four characteristics of cathode rays

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 are the three differences between plants and animals?

What is non-uniform motion? Give some examples.

(a) Express Newton's second law mathematically explaining the symbols used.
(b) Define SI unit of force from this expression.

State any three differences between mass and weight.

Write the various energy transformations that occur in the following cases:
(a) Moving a car
(b) Going up in an escalator
(c) Rotating of an electric motor
(d) Release of an arrow from a bow
(e) Lighting of an electric bulb
(f) Tuning of an FM radio receiver
(g) Gas stove burner.

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

Which are the winds that brings about rain in the most part of India?

What prevantive and control measures should be taken before storage of grains?

Everything in this universe is made up of material which scientists have named matter.A matter is said to have the following characteristics:
(a) Matter is made up of tiny particles
(b) Particles of matter have space between them
(c) Particles of matter are continuously moving
(d) Particles of matter can diffuse into each other
(e) Particles of matter attract each other
Give experiences of your daily life to justify above characteristics of matter.

What separation technique will you apply for separation of the following
(i) ammonium chloride from sodium chloride
(ii) Different pigment from the extract of flower petals.
(b) What is crystallisation?List two ways in which crystallisation technique is better than simple evaporation technique.

Write the names of compounds represented by the following formulae:
(i) CaCO₃ (ii) Al₂(SO₄)₃ (iii) K₂SO₄

Write briefly about structure and function of

(a) Mitochondria

(b) Chloroplast

(c) Golgi apparatus

A train starting from rest picks up a speed of 10 \(ms^{ -1 }\) in 100 s.It continues to move at the same speed for the next 250 s. It is then bought to rest in the next 50 s. Plot a speed-time graph for the entire motion of the train.Calculate:
(i) acceleration of the train while accelerating
(ii) retardation of the train while retarding
(iii) the total distance covered by the train.

(i) Prove that, if the earth attracts two bodies placed at the same distance from the centre of the earth with equal force, then their masses will be the same.
(ii) Mathematically express the acceleration due to gravity in terms of mass of the earth and radius of the earth.
(iii) Why is G called a universal constant?

(a) Write an expression of the work done when a force is acting on it.When will it be negative?
(b) Define 1 joule of work.
(c) Calculate the work done on an object of mass 1 kg lifted to a height of 1m.Take g=10 ms^-2 .