Q 1 – Differentiate between speed and velocity.
Speed
- Speed is measured as the ratio of distance covered to the time taken to cover.
- It is a scalar quantity as it has only direction and no magnitude.
Velocity
- The velocity of an object can be defined as the rate of change of the displacement of the object from its initial position with respect to time.
- It might sound complicated but velocity is basically speeding in a specific direction.
3 .It is a vector quantity.
Speed | Velocity |
The rate at which an object covers a certain distance is known as speed. | The rate at which an object changes position in a certain direction. |
Speed cannot be negative or zero. | It can be negative or zero. |
Speed is a scalar quantity. | It is a vector quantity. |
Example: | Example: |
Q 2 – Which law of motion gives the measure of force? Write an expression for force.
The law of motion that gives the measure of force is Newton’s second law of motion. The expression for force is given by: F=m×a
EXPLAINATION: Force = Mass × Acceleration
or, F = m × a
where F is the force applied, m is the mass of the object, and a is the acceleration possessed by the object.
Newton’s second law of motion.
Newton’s second law of motion states that the acceleration of an object is proportional to the net force applied to it and inversely proportional to its mass.
Example of Newton’s second law of motion – Throwing a ball: When a person throws a ball, they apply a force to it. The acceleration of the ball depends on the force applied and its mass. The greater the force and the lighter the ball, the greater the acceleration.
Acceleration
Acceleration is a measure of the rate of change in velocity of an object. It is a vector quantity and the reciprocal of acceleration is known as retardation.
Q 3 – Name the principle on which a rocket works.
OR
Why does a boat tend to leave the shore, when passengers are alighting from it?
Rockets work on the principle of conservation of momentum.
Or
When the passengers alight from the boat, they push the boat in backward direction. As a result, the boat has a tendency to slip back into water. This difficulty is usually overcome by the boatman by tying the boat to some rigid support.
Q 4 – If the small and big stones are dropped from the roof of a house simultaneously, they will reach the ground at the same time. Why?
If the small and big stones are dropped from the roof simultaneously they will reach the ground at the same time because the acceleration of the stone depends upon gravity but not on mass.
Acceleration due to gravity:
- It depends upon the gravitational force of any object and it is affected by the shape of the earth
- The acceleration due to gravity attracts the stone or any material towards the gravitational force
- The mass of the object does not depend upon the acceleration due to gravity
- The object which has different masses the acceleration due to gravity remains the same
- The acceleration due to gravity changes with the depth ofthe earth’s surface
Q 5 – The distance between two objects is decreased. Will the gravitational force between them increase or decrease ?
since gravitational force is inversely proportional to the square of the seperation distance between two interacting objects ,more seperation distance will results in weaker gravitational forces.so as two objects are seperated by each other.the force of gravitational attraction between them also decreases
Q 6 – What is the SI unit of acceleration due to gravity (g) ?
OR
What is the SI unit of gravitational constant G?
The gravity of Earth, which is denoted by g, refers to the acceleration that the Earth imparts to objects on or near its surface. In SI units this acceleration is measured in metres per second squared (in symbols, m/s2) or equivalently in newtons per kilogram (N/kg).
Or
Newtons kg
Explanation:
In SI units, G has the value 6.67 × 10-11 Newtons kg-2 m2. The direction of the force is in a straight line between the two bodies and is attractive. Thus, an apple falls from a tree because it feels the gravitational force of the Earth and is therefore subject to “gravity”.
Q 7 – Read the following and answer any four questions from 7 (i) to 7 (v)
Newton’s second law of motion pertains to the behavior of objects for which all existing forces are
not balanced. The second law states that the acceleration of an object is dependent upon two variables – the net force acting upon the object and the mass of the object. The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object. As the force acting upon an object is increased, the acceleration of the object is increased. As the mass of an object is increased, the acceleration of the object is decreased.
The First Law of Motion indicates that when an unbalanced external force acts on an object, its velocity changes, ie., the object is accelerated. Now, let’s study how the acceleration of an object depends on the force applied. Consider the example. A car at rest does not require much attention when parked along a road side. But the moving car, even at a low speed, may kill a person standing in its path. A small mass, such as a bullet may kill a person when fired from a gun. From these
examples it is clear that the impact produced by the objects depends on their mass and velocity.
When we combine the mass and velocity of an object, we get another quantity called momentum, which was introduced by Newton
i) Which units can be used to express force?
N
b. kg/s2
c. kg • m/s2
d. two of the above
c. kg • m/s2
ii) Newton’s second law of motion relates an object’s acceleration to
its mass.
b. its velocity.
c. the net force acting on it.
d. two of the above
c. the net force acting on it.
iii) An object is accelerating when it
a. speeds up.
b. slows down.
c. changes direction
d.any of the above
a. speeds up.
iv) Doubling the net force acting on an object
doubles its acceleration.
b. decreases it acceleration.
c. cuts its acceleration in half.
d. does not affect its acceleration.
. b. decreases it acceleration.
v) If you push a 20-kilogram mass with a force of 40 N, what will be the object’s
acceleration?
40 m/s2
b. 20 m/s2
c. 10 m/s2
d. 2 m/s
d. 2 m/s
Q 8 – Read the following and answer any four questions from 8 (i) to 8 (v) Energy is conserved. What does this really mean, and why is it true?
Water in a reservoir is more or less conserved. So the amount of water can always be calculated from the amount that was there some time ago, plus the amount that has come in, minus the amount that has gone out (you may have to take account of evaporation as well as water drawn off).
Energy is similar. If you take any volume of space, then the total energy inside that volume at a given time is always the amount that was there earlier, plus the total amount that has come in through the surface, minus the total amount that has gone out through the surface.
The swinging pendulum can either possess the kinetic energy or potential energy.
When the bob is at position B it possesses only the potential energy and not the kinetic
energy. When it moves towards the point A its potential energy goes on decreasing. And kinetic energy goes on increasing.
When it reaches at point A it possesses only kinetic energy.
When it again tends to move towards the point C kinetic energy starts getting converted to potential energy.
Thus at extreme positions B and C, the potential energy is maximum. While at mean position kinetic energy is maximum. Thus the total energy at every instant of a time is constant. This proves the law of conservation of energy.
The law of conservation of energy is a law of science that states that energy cannot be created or destroyed, but only changed from one form into another or transferred from one object to another
i) The energy stored in wound watch spring is
a) K.E
b) P.E
c) Heat Energy
d) Chemical Energy
b) P.E
ii) If the stone is thrown up vertically and return to the ground, its potential energy is
maximum
a) During the upward journey
b) At the maximum height
c) During the return journey
d) At the bottom
b) At the maximum height
iii) The potential energy of a simple pendulum will be maximum when it is
a)At the turning point of oscillation
b)At equilibrium
c)In between above two cases
d)Any time
a)At the turning point of oscillation
iv) SI unit Of energy
a) Joules
b) Newton
c)m/s
d)metre
a) Joules
v) Kinetic energy of the bob of a simple pendulum is maximum
a)at the mean position
b)at the extreme left position
c)at the extreme right position
d)none of these
a)at the mean position
Q 9 – The nucleons are
a. Protons and electrons
b. Neutrons and electrons
c. Protons and electrons
d. Protons and neutrons
d.Protons and neutrons
Q 10 – Name the isotope of hydrogen having no neutron.
a. Proton
b. Protium
c. Deuterium
d. Tritium
c. Deuterium
Q 11 – The electrons present in the outermost shell are called
a. Valence electron
b. Valency electron
c. Duplet electrons
d. Octet electrons
a. Valence electron
Q 12 – The isotope used in the treatment of cancer
a. CO-60
b. C-14
c. Co-60
d. U-235
a.Co-60
Q 13 – Water is formed from hydrogen and oxygen.
a. What is the correct chemical formula of water?
b. What is the ratio by mass of hydrogen and oxygen in water?
c. Why is water considered as compound?
d. What is the gaseous form of water?
Formation of water from hydrogen and oxygen is a combination reaction because hydrogen and oxygen are combining to form single product. The reaction occurs as follows: 2H2(g)+O2(g)→2H2O(l)
(a) For example, H2O (water) molecule represents that water is made up of 2 atoms of hydrogen element and one atom of oxygen
(b) The ratio of hydrogen atoms to oxygen atoms used to make water molecules is always 2:1, no matter how many water molecules are being made.
(c) Water is a compound because it is made up of water molecules. There is no such thing as water atoms. Water molecules are made of hydrogen and oxygen atoms, in the definite proportion of two hydrogens for one oxygen.
(d) The gaseous state of atmospheric water is termed water vapor or simply vapor.
Q 14 – Plasma membrane is called a selectively permeable membrane. Justify
Plasma membrane allows some material to pass through it while on the same time it blocks other material from entering through it… This is mainly because of the sizes and polarity of molecules. In other words its selects materials that can enter the cell… that’s the reason it is called as selectively permeable membrane.
Q 15 – What are genes? Where are they located?
OR
Why is nuclear region in prokaryotes poorly defined?
Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body. Chromosomes are structures within cells that contain a person’s genes. Genes are contained in chromosomes, which are in the cell nucleus.
Or
In prokaryotic cells, nucleus is not defined properly because, it is not surrounded by nuclear membrane, with inner nucleoplasm and chromatin material. So, it is poorly defined and it is called nucleoid or genophore.
Q 16 – A person suffering from HIV-AIDS cannot fight even minor infections. Why?
OR
Who discovered vaccine for the first time? Name two diseases which can be prevented by using vaccines.
Lymphocytes (one of the WBC) present in the blood are destroyed by HIV. This makes the infected individuals more vulnerable to other fatal diseases and infections. Hence, an infected person’s body is not able to fight even minor infections like cold and minor infections can be fatal in this disease.
Or
Edward Jenner discovered ‘vaccine’ for the first time. Diseases which can be prevented by vaccination are: Small pox. Polio.
Q 17 – A person met with an accident in which two long bones of the hand were dislocated. What could be the reason?
A person met with an accident in which two long bones of the hand were dislocated and the reason is because of a ligament break.
For question number 18 and 19, two statements are given- one labeled Assertion (A) and the
other labeled Reason (R). Select the correct answer to these questions from the codes (a), (b),
(c) and (d) as given below:
ASSERTION (A): Mitochondria are strange organelles
REASON (R): The energy required for various chemical activities needed for life is released by
mitochondria in the form of ATP (Adenosine triphopshate) molecules.b) Both A and R are true, but R is not the correct explanation of the assertion.
c) A is true, but R is false.
d) A is false, but R is true.
Q 18 – ASSERTION (A): Viruses lack any membranes
REASON (R): Viruses do not show characteristics of life until they enter a living body and use its cell machinery to multiply.
OR
ASSERTION (A): Mitochondria are strange organelles
REASON (R): The energy required for various chemical activities needed for life is released by
mitochondria in the form of ATP (Adenosine triphopshate) molecules.
a) Both A and R are true, and R is correct explanation of the assertion.
Or
a) Both A and R are true, and R is correct explanation of the assertion.
Q 19 – ASSERTION (A): Salmonella typhi, causes peptic ulcers
REASON (R): Patients could be cured of peptic ulcer only when the bacteria were killed off from the stomach.
d) A is false, but R is true.
Q 20 – Read the following and answer any four questions from 20 (i) to 20 (v)
A group of cells that are similar in structure and/or work together to achieve a particular function forms a tissue. The growth in plants is limited to certain regions, while this is not so in animals. There are some tissues in plants that divide throughout their life. Cell growth in animals is more uniform.
I) Select the correct statement regarding meristematic tissues?
a. They are found at specific locations in the animal body
b. They have cells with thick secondary walls
c. They perform the function of growth and division
d. Both a and c
d. Both a and c
II) Match column 1 with column 2 and select the correct option from the given codes.
Column 1 | Column 2 |
A. Food Storage | Parenchyma |
B Food conduction | Phloem |
C. Mechanical strength | Sclerenchyma |
D. Water Conduction | Xylem |
III) Which of the following statement is correct about the cell shown in the figure?
Cells of this tissue are highly specialised for being stimulated and then transmitting the stimulus very rapidly
b. It consists of a cell body with a nucleus and cytoplasm, from which long thin hair-like parts arise
c. Each of this tissue has a single long part, called the dendrite, and many short, branched parts called axons.
d. P receives nerve impulse from Q and conveys it to other cells
b.It consists of a cell body with a nucleus and cytoplasm, from which long thin hair-like parts arise
IV) The tissue shown here is:
a.Simple squamous epithelial tissue
b. Striated muscle tissue
c. Areolar tissue
d. Ciliated columnar tissue
d.Ciliated columnar tissue
V) Which of the following is incorrectly matched?
a. v and vi only
b. ii, iv and vi only
c. iii and iv only
d. iii and v only
a. v and vi only
Q 21 – i)Identify the type of motion in the following graph .
ii)What does the area under a velocity time graph represent?
1 Graph (b) represents constant speed.
2 Graph (a) represents uniform acceleration.
(ii) The area under a velocity graph represents the displacement of the object.
Q 22 – i )Define kinetic energy with example.
ii)What is the Kinetic Energy of a 150 kg object that is moving with a speed of 15 m/s?
i) Kinetic energy is the energy of motion, observable as the movement of an object or subatomic particle. Every moving object and particle have kinetic energy. A person walking, a soaring baseball, a crumb falling from a table and a charged particle in an electric field are all examples of kinetic energy at work.
ii) Given:
The Mass of the object = 150 Kg.
The Speed of the object = 15m/s.
To Find:
The kinetic energy of the object.
Solution:
The formula used for calculating the kinetic energy is,
K.E = ½MV²
Where,
K.E is the kinetic energy of the object.
M is the mass of the object.
V is the velocity of the object.
Now, putting the values we have in the equation, we get,
K.E = ½ x 150 x (15)²
= 16,875 joules
Hence, the Kinetic energy of the object is 16,875 joules.
Q 23 – What kind of mixture is solution? Name the different constituents of a solution.
A solution is a homogeneous mixture of two or more substances. A solution has a solvent and a solute as its components. The component of the solution that dissolves the other component in it (usually the component present in larger amount) is called the solvent.
Q 24 – What are ions? Write the symbol of sodium ion and chlorine ion?
The valance of each element is indicated as a superscript on the symbol of the element with a + sign for anions and a − sign for cations. Thus, the symbol of the sodium ion is Na+ and that for the chlorine ion is Cl−.
Q 25 – a. Write two points of difference between rough endoplasmic reticulum and smooth endoplasmic reticulum.
b. What is membrane biogenesis?
OR
Draw a diagram of an animal cell and label at least eight organelles in it.
a.RER consists of the parallel sheets of the membrane. Smooth ER is located near the cell membrane while Rough ER is present near the cytoplasm of the eukaryotic cells. Smooth ER is derived from rough endoplasmic reticulum by sacrificing the ribosomes, whereas Rough ER originates from the nuclear membrane.
b.Membrane synthesis or membrane biogenesis is a process of building cell membrane. It is a dynamic process, i.e., some of the membrane proteins and lipids are replaced with newly made proteins and lipids. This is an ongoing process. The proteins and lipids required for membrane biogenesis are synthesized by endoplasmic reticulum.
Or
Labelled diagram of animal cell.
Q 26– a. Identify the plant tissue shown below.
b. What is its function?
b. A function is defined as a relation between a set of inputs having one output each. In simple words, a function is a relationship between inputs where each input is related to exactly one output. Every function has a domain and codomain or range.
Q 27 – i)Differentiate between mass and weight.
ii)Determine the gravitational force if the mass of two bodies are 80 kg and 1200 kg and they are separated by a distance of 10m.( G = 6.67 x 10–11 N m2/kg2.)
i) The difference between Mass and Weight is Mass is a measure of Inertia and Weight is a measure of Force. Many often tend to use these two terms in the same manner. However, this is not correct at all. We will help you study the multiple differences that are between mass and weight. Thus, we will start by defining the respective terms to set a strong base. Only after knowing what they are can you understand their differences. So, let’s dive right in!
ii) m1 = 80 kg, m2 = 120 kg, r = 10 m,
G = 6.67 × 10-11 Nm2 / kg2, F = ?
= 64.032 x 10-10 N
The force of gravitation between two objects = 64.032 x 10-10 N.
Q 28 – Write the correct symbol and charge of electron, proton and neutron?
Particle – proton
Symbol – p+
Relative Charge – +1
Particle – electron
Symbol – e−
Relative Charge – −1
Particle – neutron
Symbol – n
Relative Charge – 0
Q 29 – Calculate the formula mass unit of
i)NH3
ii)H2SO4
iii)CaCl2 (atomic mass of N=14, Cl=35.5, S=32, Ca=40, O =16)
i) NH3
Atomic mass of N+3 + (atomic mass of hydrogen)
= 14+3
= 17 u
ii) H2SO4
1 x 2 + 32 + 16 x 4
= 2+ 32+64
= 98 u
iii) Cacl2
Atomic mass of Ca = 40
Atomic mass of Cl = 35.5(2)
Formula unit mass of Cacl2 = 111u
Q 30 – (a) Identify the solute and solvent in tincture of iodine’
(b) Name the technique to separate
(i) Butter from curd
(ii) Salt and sea water
(iii) Camphor from salt
➡ In the tincture of iodine, the solvent is alcohol and water while the solute is iodine.
➡Butter from curd is separated by the technique of centrifugation.
➡The salt can be separated from the sea water by a simple process of evaporation.
➡the mixture of camphor and sodium chloride can be separated by the process of sublimation.
Q 31 – a. Aquatic plants have the ability to float rather than being submerged in water. How?
b. List the different elements of xylem.
c. Why do plants living in dry habitats have thicker epidermis?
OR
a. Why are voluntary muscles called straited muscles?
b. Which type of muscles are found in the iris of eye, ureters and in the bronchi of the lungs
c. In which part of the body cuboidal epithelium is found? What is its function?
- Because they have aerenchyma which helps them to float.
- Xylem parenchyma, xylem fibre, tracheids and vessels
- To reduce the amount of transpiration.
Or
a.Striated muscles are the skeletal muscles which are also known as voluntary muscles. They are called voluntary muscles because their action is under the control of the somatic nervous system and their movement can be controlled by us (Eg: Bicep muscles), unlike as in the case of involuntary muscles (Eg: cardiac muscles). The muscle fibers of striated muscles are multinucleated and cylindrical. They appear striated due to the presence of alternate light and dark bands when viewed through the microscope.
(b) Smooth muscle is an involuntary non-striated muscle.it is found in visceral organs.eg:iris and blood vessels.
(c) Simple cuboidal epithelium: This type of epithelium is typically found in glandular (secreting) tissue and kidney tubules. Simple columnar epithelium: This type of epithelium is often specialized for absorption and usually has apical cilia or microvilli. These cells line your stomach and intestines.
Q 32 – In brief state explain what happens when:
a. Dry apricots are left for some time in pure water and later transferred to sugar solution.
b. Golgi apparatus is removed from cell
c. The plasma membrane of a cell breaks down
a) When we put dried raisins or apricots in plain water and leave them for some time cell gains water and swells. If we put some seeds into a concentrated solution of sugar you will observe it loses water and consequently shrinks.
b) This stops the formation of vesicles and transport of proteins and lipids are stopped by the removal of the Golgi apparatus.
(c) Breaking of the plasma membrane leads to the scattering of the cell organelles as it forms the basic supporting unit of the cell.
Q 33 – a. State two conditions essential for good health.
b. What is the principle of immunization?
a.Nutritious food and Exercise are two important conditions for a healthy body.
b.The basic theory of immunization is that the body begins to produce antibodies against it upon administration of the vaccine so that the individual is safe from disease.
Q 34 – i)Differentiate between uniform and non-uniform motion
ii)Derive velocity time relation graphically.
iii )A body starts from rest accelerate to a velocity of 20 m/s in a time of 10 s. Determine the
acceleration of the boy.
OR
i)Derive an expression for kinetic energy of an object.
ii) If the velocity of an object is doubled. What will be change in its kinetic energy?
i) Uniform motion is the rectilinear motion of a body when it covers a similar distance in similar time intervals while non-uniform motion is the rectilinear motion of a body when it covers unequal or variable distance in similar time intervals.
iii) Given :
- Initial velocity (u) = 0 m/s
- Final velocity (v) = 20 m/s
- Time interval (t) = 10 s
To Find :
- Acceleration of the body
Solution :
Concept : We are given time interval, initial velocity and Final velocity. We can find value of acceleration using Kinematics equations. Here we will use 1st equation of the kinematics .
Calculation :
➠ v = u + at
⇒at = v – u
⇒a = (v – u)/t
⇒a = (20 – 0)/10
⇒a = 20/10
⇒a = 2
Acceleration of body is 2 m/s²
_______________________________
- Acceleration is defined as Rate of change of velocity.
- It is a vector quantity.
- acceleration is denoted by “a”.
- SI unit of acceleration is m/s²
Q 35 – (a) Differentiate between isotope and isobar. Give one example of each
(b) Write any three important application of isotopes?
OR
From the symbol 1840Ar, Write down the
(i) Electrons, protons and neutrons
(ii) Valence electrons and valency
(iii) Electronic configuration
(iv) Atomic number, Mass number and
(v) Draw the structure of Argon.
(a) Isobar are elements that differ in chemical properties but have the same physical property. So, we can say that isobars are those elements that have a different atomic number but the same mass number. In contrast, Isotopes are those elements having the same atomic number and different mass numbers.
(b) Isotopes:
Isotopes are atoms of the same element having the same atomic number but different mass numbers.
Isotopes can also be defined as the variants of chemical elements that possess the same number of protons and electrons, but a different number of neutrons.
The chemical properties of all the isotopes of an element are the same.
For Ex: Isotopes of Hydrogen are 1H1,1H2,1H3
Application of Isotopes
1) An isotope of Uranium (i.e. Uranium-235) is used as a fuel in a nuclear reactor.
2) An isotope of cobalt (i.e. cobalt-60) is used in the treatment of cancer.
3) An isotope of iodine (i.e. iodine-131) is used in the treatment of goiter.
4) An isotope of carbon (i.e.carbon-14) is used in the carbon dating technique (through which the age of fossils can be determined)
Q 36 – Explain with examples the different means by which infectious diseases can spread?
Infectious diseases commonly spread through the direct transfer of bacteria, viruses or other germs from one person to another. This can happen when an individual with the bacterium or virus touches, kisses, or coughs or sneezes on someone who isn’t infected.