MPTET Varg 2 Science Mock Test - 3 - MPTET MCQ

The correct answer is Water.

Key Points

Abiotic Factors:

• Abiotic factors refer to all the non-living, i.e. chemical and physical factors present in the atmosphere, hydrosphere, and lithosphere.
• Water, Sunlight, air, precipitation, minerals, and soil are some examples of abiotic factors.
• These factors have a significant impact on the survival and reproduction of species in an ecosystem.
• For instance, without an adequate amount of sunlight, autotrophic organisms may not be able to survive.
• When these organisms eventually die, it will create a shortage of food for primary consumers.
• This effect cascades up the food chain, affecting every organism. Consequently, it leads to an imbalance in the ecosystem.

Renewable resource:

• Renewable energy is energy that is produced from natural processes and continuously replenished.
• A few examples of renewable energy are sunlight, water, wind, tides, geothermal heat, and biomass. Hence, option 3 is correct.
• The energy that is provided by renewable energy resources is used in 5 important areas such as air and water cooling/heating, electricity generation, the rural sector, and transportation.
• The existence of renewable energy resources is spread over a wide geographical area in comparison to conventional energy resources which are often concentrated in a limited number of countries like oil and gas are mostly concentrated in Middle East countries.
• The use of renewable energy resources in energy generation is resulting in less pollution and has a significant effect on economic benefits and energy security.

The correct answer is distillation.

Concept:

Mixture:

• A mixture is a substance that consists of two or more elements or compounds not chemically combined together.
• For example, a mixture of salt and sand.

Separation of mixtures:

• The constituents of mixtures have different physical properties such as density, size of particles, solubility, etc.
• These differences are used to separate the constituents of the mixtures.

Explanation:

Distillation:

• It is used to separate two or more miscible liquids that have a large difference between their boiling points.

So, for separating acetone and water, distillation can be used.

Additional Information

Separating funnel: It is used to separate a mixture of two immiscible liquids, like oil and water using a separating funnel.

Chromatography:  This method is used to separate two or more dissolved solids which are present in a solution in very small quantities.

Fractional distillation: It is used to separate two or more miscible liquids that have small differences between their boiling points.

Concept:

Energy

• Energy is the capacity to do work. 
• It is neither created nor destroyed. 

Units of Energy

Joule:

• Joule is the SI unit of Energy. 

Electron volt: 

• It is the amount of energy required to move an electron from one point to another across the potential difference of 1 volt. 
• 1 electron volt = 1.602 × 10-19 Joule

Erg:

• The unit of energy expressed in centimeter-gram-second (cgs) is called erg.
• 1 erg = 10-7 J

Calorie:

• The amount of energy required to raise the temperature of 1 gram of water by 1°C or 1 Kelvin is called Calorie.
• 1 calore = 4.186 J

KwH: 

• This is a commercial unit of energy. It is the energy consumed when a device with power rating 1 Kilowatt is used for 1 hour. 

1 KwH = 3.6 × 10 6 J

Newton-meter

• Work done is said to be 1 joule, when a force of one newton actually moves a body through a distance of one meter in the direction of applied force.

Watt

• It is the work done in unit time.
• Watt is the unit of power.

Science aims at enabling students to develop their communication skills to be able to understand scientific information, such as data, ideas, arguments, and investigations, and communicate it using appropriate scientific language in a variety of communication modes.

Key Points 

Scientific Attitude: Scientific attitude is caring about evidence and being willing to change theories on the basis of new evidence.

• The scientific attitude reveals why even a failed theory can help us to understand what is special about science.
• It is the grounding of science in evidence that offers a uniquely powerful tool in the defense of science.
• Scientific attitude helps to tackle problems objectively without bias promoting logical thinking.

The Characteristics of Scientific Attitude: 

• Scientific attitude refers to critical observation, inquisitiveness, broadmindedness, and open-mindedness.
• An individual is open-mindedness, curiosity, judgment based on verified facts, ready to test and verify conclusions, faith in cause and effect relationships, collecting and reporting scientific data, critical in observations, accepting no conclusions a final or ultimate, and more faith in the books written by specialists in their respective fields, etc.
• Scientific attitude includes the following habits of thinking, the habit of accuracy in all operations, have objectivity in approach to problems, including accuracy in calculation, observation, and report.
• Scientific attitude is the combination of many qualities and virtues, which is reflected through the behavior and action of the person. 

Hence, from the above-mentioned points, it becomes clear that Hard work is not a quality of scientific attitude.

The correct answer is Esters.

Key Points

• ​An ester is a chemical compound derived from an oxoacid.
• Esterification is the general name for a chemical reaction in which two reactants.
• Esters compound is obtained by the reaction of an oxoacid with a hydroxyl compound, such as alcohol or phenol
• Esters are common in Organic chemistry and biological materials.​

Additional Information

• In organic chemistry, a carbonyls group is a functional group composed of a carbon atom double-bonded to an oxygen atom.
• Amines are compounds and functional groups that contain a basic nitrogens atom with lone pair.
• A carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group.

Key Points

• Lungs are the vascularised bags that are used by the terrestrial forms for the exchange of gases (pulmonary respiration).
• Humans have a pair of lungs that are covered by a double-layered pleura or pleural membrane, with pleural fluid between them.
• It reduces friction on the lung surface.
• The outer pleural membrane is in close contact with the thoracic lining whereas the inner pleural membrane is in contact with the lung surface.

​

Additional Information

• Pericardium - The heart is protected by a double-walled membranous bag, pericardium, enclosing the pericardial fluid. 
• The peritoneum -  is the membrane that lines the visceral cavity and enclosed the visceral organs.
• Perichondrium -  is a layer of connective tissues that enclose or surrounds the cartilage of a developing bone.

Concept-

• The fishery is an industry devoted to the catching, processing, or selling of fish, shellfish, or other aquatic animals.
• A large number of our population is dependent on fish, fish products, and other aquatic animals such as prawns, crab, lobster, edible oysters, etc., for food.
• Fishes can be divided into two broad categories - freshwater fishes & marine fishes.
• Some of the freshwater fishes which are very common include Catla, Rohu, and common carp.

Key Points

Some of the marine fishes that are eaten include – Hilsa, Sardines, Mackerel, and Pomfrets.

Additional Information

• Fisheries have an important place in the Indian economy.

• It provides income and employment to millions of fishermen and farmers, particularly in the coastal states.
• For many, it is the only source of their livelihood. In order to meet the increasing demands on fisheries, different techniques have been employed to increase production.
• For example, through aquaculture and pisciculture, we have been able to increase the production of aquatic plants and animals, both fresh water and marine.
• This has led to the development and flourishing of the fishery industry, and it has brought a lot of income to the farmers in particular and the country in general.

Concept:

Atmospheric pressure:

• Atmospheric pressure is defined as the weight of a column of air contained in a unit area from the mean sea level to the top of the atmosphere or we can say the pressure exerted by the weight of air on the earth's surface is atmospheric pressure.
• The SI unit is millibar.
• The atmospheric pressure at sea level is 1013.2 millibar.
• The pressure of the atmosphere is measured by a mercury barometer or aneroid barometer.
• As we go at a high altitude, the pressure falls rapidly. 
• The atmospheric pressure is highest at sea level and decreases with height.

Explanation:

• The atmospheric pressure is comparatively low at high altitudes than at low altitudes because with the increase in altitude, the number of gas particles decreases, thus the collision between the gas particles also decreases. So, the pressure also decreases. 
• Whereas the atmospheric pressure is high at low altitudes at the seashore. So, the Reason is incorrect.
• At high altitudes. with the decrease in air pressure, the vapor pressure exceeds and due to the increase in vapor pressure water boils easily. Thus, the boiling temperature of water decreases. So, Assertion is also incorrect.

Therefore, from the above discussion, we can say that Both Assertions and Reason are false.

Concept:

• Introduction to the class Aves: 
• All the birds are included in the class Aves.
• Their body is boat-shaped and divided into head, neck, trunk & tail.
• Their body is covered with soft feathers called ''plumage''
• Birds are warm-blooded animals or homeothermic i.e. their temperature remains constant with respect to the outside temperature.
• They are subdivided into two sub-classes: a.) Archaeornithes b.) Neornithes

Explanation: 

• Birds have long hollow bones, filled with air cavities, these bones are called pneumatic bones.
• Pneumatic bones make the body light in weight and help in flying.

Additional Information

• Mammals have a bony endoskeleton, the skull is dicondylic. Vertebrae are acoelous or amphibian type i.e. centrum is flat at both sides. Cartilagenous pads are found at the edges of the centrum, which are called epiphysis.
• Reptiles have a chevron bone found in the caudal vertebrae.
• Osteichthyes: It is a class of fishes that has bones in their endoskeleton so they are called Bony fishes.

The correct answer is Nucleoid and Chromatin.

Key Points

• The genetic material of prokaryotes and eukaryotes is DNA.
• DNA (deoxyribonucleic acid) combines to form the polynucleotides and thus form the chromosomes.
• Prokaryotes do not contain a well-defined nucleus. It has nucleoids inside the cell.
• It is this nucleoid that contains its genetic material.
• Eukaryotes have true nuclei.
• Its nucleus represent chromatin.
• The chromatin consists of DNA and proteins.
• Nucleoid and Chromatin correctly represent the genetic material in prokaryotes and eukaryotes.

Additional Information

The Correct answer is Option Fig. 3

• The electronic dot and cross structure of ethene is: 

• As we know that, the molecular formula of Ethene is C₂H₄. Hence, the above diagram shows the correct dot and cross structure of Ethene.
• Ethylene/Ethene is an unsaturated hydrocarbon.
•  It is a colorless flammable gas with a faint sweet and musky gas.
• It is naturally produced and released by most fresh fruits and vegetables as a natural ripening agent.
• It is also known as the natural ripening hormone.

An open-ended question is one that requires thinking creatively to provide an answer or in an easy way can say those questions which helps the student to make other related questions from the asked question is open-ended.

While the close-ended question is opposite to that of an open-ended question.

• Open-ended questions can not be simply answered as yes or no or in a static response, they are like free to go through your own way.
• The answer varies from person to person.
• The open-ended question helps children to think logically and critically about the situation/problem.

Important Points

The statement" "Only open-ended questions work while teaching science" is partially correct since science is a subject where some questions can have only one answer so it doesn't always work.

Disadvantages of Open-Ended Questions

• Different answers may be received from the respondents on the same question.
• Responses can be vague, irrelevant, or not to the point.
• Many interpretations of the same question may not lead to valuable analysis.
• Coding of the responses is not possible.
• The respondent needs more time to answer.

Hence, we can conclude that no doubt open-ended questions are best in creating creativity and assessing knowledge but it is not always work in teaching science factual concepts where proof is needed.

The Correct Answer is Earth and Sun.

Key Points

An astronomical unit, often abbreviated as AU, is a unit of length that is approximately equal to the distance from the Earth to the Sun.

• It's used primarily in astronomy to describe the distances between objects in the solar system and is based on the mean distance from the center of the Earth to the center of the Sun.
• The exact definition of an astronomical unit has been refined over time as our understanding and measurements of the solar system have improved.
• As of 2012, the International Astronomical Union (IAU) defines 1 AU as exactly 149,597,870.7 kilometers, which is about 93 million miles.
• Using this standardized measure allows astronomers to express and compare distances of objects within the solar system without using very large numbers.
• For instance, one could say that Jupiter is approximately 5.2 AU from the Sun, rather than saying it is approximately 778 million kilometers away.

Additional Information

The other options provided:

• Earth and Mercury: The distance between Earth and Mercury varies greatly due to their elliptical orbits and different orbital speeds. However, it is significantly less than 1 AU.
• Earth and Moon: The distance from the Earth to the Moon is only about 0.0026 AU. This is much less than the distance from the Earth to the Sun, which defines an AU.

• Middle lamella is composed of Pectin.
• It consists of calcium and magnesium pectate however the amount of calcium is more thus, the major element present inside the middle lamella is Calcium (Ca)
• The middle lamella serves as a cementing layer between the primary walls of adjacent cells.
• The two cells can be separated from each other by the dissolution of the middle lamella by proteolytic enzymes.

The correct option is Calcium. 

Concept:

• Cells are the structural & functional unit of life.
• Cells that have membrane-bound nuclei are called eukaryotic whereas cells that lack a membrane-bound nucleus are prokaryotic.
• In both prokaryotic and eukaryotic cells, a semi-fluid matrix called cytoplasm occupies the volume of the cell.
• Besides the nucleus, the eukaryotic cells have other membrane-bound distinct structures called organelles like the endoplasmic reticulum (ER), the Golgi complex, lysosomes, mitochondria, microbodies and vacuoles.
• The prokaryotic cells lack such membrane-bound organelles.
• Ribosomes are non-membrane bound organelles found in all cells – both eukaryotic as well as prokaryotic.
• The eukaryotic can be further classified into two types - Animal cells & Plant cells.

Explanation:

• All eukaryotic cells are not identical.
• Plant and animal cells are different as the former possess cell walls, plastids and a large central vacuole which are absent in animal cells.
• On the other hand, animal cells have centrioles which are absent in almost all plant cells.

Below is the table to compare animal & plant cells.

Hence, the combination of components of an animal cell is the Cell membrane, Cytoplasm, Nucleus, Vacuole.

Explanation:

The sound is all around us and can be measured to protect and inform us, as some sounds are not safe. In fact, loud noise can actually damage our hearing. So, the intensity of a sound is measured using decibels.

• As the human ear is incredibly sensitive, you can hear everything from your fingertip brushing lightly over your skin to a loud thunderclap. As far as power is concerned, the sound of the thunderclap is approximately 1,000,000,000,000 times more powerful than the smallest audible sound. 
• Decibel is the unit of sound. Its symbol is dB.
  • On the decibel scale, 0 dB is the smallest audible sound.
  • Humans can hear from 10 dB - 120 dB.
• A sound 10 times more powerful is 10 dB.
• A sound 100 times more powerful than near total silence is 20 dB.
• A sound 1,000 times more powerful than near total silence is 30 dB.

Important Points

• The audible range of sound for human beings extends from about 20 Hz to 20000 Hz (one Hz = one cycle/s). Children under the age of five and some animals, such as dogs can hear up to 25 kHz (1 kHz = 1000 Hz). 

Concept:

• When a point mass is suspended with the help of a inextensible string or rod of negligible mass and does the to and fro motion about its mean position is called as simple pendulum.
• For a simple pendulum the time period of swing of a pendulum depends on the length of the string and acceleration due to gravity.

The above formula is only valid for small angular displacements.

Where, T = Time period of oscillation, l = length of the pendulum and g = gravitational acceleration

Explanation:

• According to the definition of the simple pendulum the string or rod should be inextensible. When we replace it with a rubber band which is not an inextensible material then the time period of the pendulum will get changed/altered. Hence option 1 is correct and option 2 is wrong.
• There is no perfect mathematical relation of the material with the time period so we can’t say the exact change in time period. Hence options 3 and 4 are not correct.

The correct answer is Cell wall.

Key Points

• The nonliving part of a tomato cell is its cell wall because the cell wall mainly constitutes nonliving cellulose.
• The cell wall forms the outer covering for the cell membrane of Bacteria, Fungi, Algae, and Plants.
• It gives the cell a definite shape.

• The plant cell wall is made up of cellulose and pectin.

• The cell wall also acts as the first line of defence against pathogens.

​Additional Information

• The Chloroplast is a double membrane-bound cell organelle.
• Out of the two membranes, the inner membrane is relatively less permeable. (the outer membrane contains porins).
• The space limited by the inner membrane is called the stroma.
• The Nucleus is a double membrane-bound dense protoplasmic body, which controls all the cellular metabolism and encloses the genetic information of the cell.
• It is considered the controller or director of the cell.
• The Cell membrane is the selectively permeable living boundary of the cell.
• It is also called Biomembrane or Plasma membrane.

Concept:

Molecule: 

The smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms. 

• S₈ is the Octasulfer molecule which has 8 Sulfer atoms.

Compound: 

A compound is a material composed of two or more components. Water, carbon dioxide, and table salt are some examples of compounds.

• O₃ is an ozone molecule, not an element the example of compounds are H₂O and CO₂.

Anion: 

A negatively charged ion is called an. 'anion' and the positively charged ion, a. 'cation'.

• N^3- is an anion because it is negatively charged.

Element: 

An element is a substance that cannot be split up into two or simpler substances by the means of chemical methods of applying heat, light, or electric energy.,

• Ag, Au, Mg, Co, etc. all are Examples of Elements.

Explanation:

(i) S8 is a molecule. - Correct

(ii) 03 is compound. - Incorrect

(iii) N3- is an anion. -  Correct

(iv) Co is an element. - Correct

CONCEPT:

• Angular velocity (ω): How fast the angular position or orientation of an object changes with time or How fast an object rotates or revolves relative to another point is known as angular velocity.
  • Angular velocity in terms of RPM (revolutions per minute) 

ω = 2 π f / 60

where ω is in terms of radian per second and f is in revolution per minute.

• Angular acceleration (α): The rate of change of angular velocity is known as angular acceleration.

The relation between α and changing ω is given by: 

ω₁ = ω₀ + α t

where ω1 is the final angular velocity, ω₀ is the initial angular velocity α is the angular acceleration.

CALCULATION:

Given that f₀ = 1800 rpm; f₁ = 3000 rpm; t = 20 sec.

ω₀ = 2 π f₀ / 60 = 2 π 1800 / 60 = 60π 

ω₁ = 2 π f₁ / 60 = 2 π 3000 / 60 = 100π 

ω1 = ω0 + α t

100π = 60π + α 20

α = 2π rad/sec²

So the correct answer is option 3.

Important Point

• Three equations to be used when α is constant

1. ω1 = ω0 + α t
2. θ = ω0t + 1/2 α t²
3. ω1² = ω0² + α t²

​where ω1 is the final angular velocity, ω₀ is the initial angular velocity, α is the angular acceleration and θ is angular displacement.

The correct answer is option 1 i.e. Strength of the intermolecular forces of attraction.

Intermolecular forces

• Intermolecular forces are the attractive and repulsive forces that arise between the molecules of a substance.
• Intermolecular forces are mainly responsible for the physical characteristics of the substance.
• The stronger the noncovalent interactions between molecules, the more energy that is required, in the form of heat, to break them apart.
• The boiling point and melting point of a substance is proportional to the strength of its non-covalent intermolecular forces i.e. the stronger the intermolecular forces, the higher the boiling point and melting point. Hence option 1 is correct.
• The strongest intermolecular force is the hydrogen bond.
• The weakest intermolecular forces are London dispersion forces.

Concept:

• Evaporation is the conversion of liquid into its vapour, below the boiling point of the liquid.
• During evaporation, a small fraction of particles at the surface, having higher kinetic energy, is able to break away from the forces of attraction of other particles and gets converted into vapour.
• Boiling is the process in which a liquid is converted into its vapour when heated to its boiling point.

Explanation:

Thus, the difference between boiling and evaporation is that evaporation can take place at any temperature while boiling cannot.

Explanation:

The burning of pop sound signifies the Presence of hydrogen. 

• When Zinc metal is kept in HCl, a chemical reaction takes place. The reaction is:

Zn + dil. HCl → ZnCl2 + H2

• The observations will be:
  • A colourless odourless gas is evolved.
  • The colour of the salt changed to white.
• The gas evolved is Hydrogen, and it burns with a 'pop' sound.

​

• The salt colour changes to white due to the formation of Zinc Chloride, which is white in colour.
• So, the correct option is Acid metal reaction. 

Additional Information

• The burning of magnesium forms magnesium powder which is white in colour. 
• Acid-base reactions form salt and water. The reaction is known as the neutralisation reaction.
• The formation of slaked lime (Ca(OH)₂) from quick lime (CaO) is an exothermic reaction and do not form any gas. 

CONCEPT:

• Thrust on the top of the table is due to the weight of the wooden block. Now,
• Weight of the block,

⇒ F = mg      ...(1)

⇒ Pressure (P) = F /  A      ...(2)

Where A = Cross-section of the block touching the surface, m = Mass of the wooden block 

CALCULATION:

Given: m = 2 kg,  A = 30 cm ×10 cm = 0.30 m × 0.10 m = 0.03 m2 , Dimensions of block = 30 cm × 15 cm × 10 cm

• Using equation 1,

⇒ F = mg = 2 x 10 = 20 N

• Using equation 2,

⇒ P = 20 / 0.03 = 666.67 N/m2

So the correct answer is option 4.

Methyl Alcohol is known as a wood spirit.

• It is a chemical that has the CH₃OH formula.
• It acquired the name wood alcohol because it was once developed mainly through the destructive wood distillation.
• It is produced primarily industrial through the hydrogenation of carbon monoxide.
• It is a light, volatile, colourless, flammable liquid with a distinctive smell.

The correct answer is Positive.

Key Points

• Positive work done means that force is parallel to displacement.
• When a horse pulls a cart, it gives force in the forwarding direction.
  • If the force is enough to displace the cart, the cart will displace in the same direction as the exerted force by the horse. 
  • So the work done is positive.

Additional Information

• Negative work done means that force is opposite to displacement.
  • Example: when a positive charge is moved towards another positive charge.
• If the force is perpendicular to the displacement and if either the force or the displacement is zero, work done will be zero.
  • Example: when a coolie travels on a platform with a load on his head.

The correct answer is 76 cm of Hg.
Key Points

• Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth.
• The standard atmosphere (symbol: atm) is a unit of pressure defined as 101,325 Pa (1,013.25 hPa), which is equivalent to 1013.25 millibars, 760 mm Hg, (or 76 cm Hg) 29.9212 inches Hg, or 14.696 psi.
• The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth; that is, the Earth's atmospheric pressure at sea level is approximately 1 atm.

Additional Information
Temperature Conversion Formula Table

The correct answer is Down's Syndrome.

• Down's Syndrome is caused due to an extra 21st chromosome.

Key Points

• Down's Syndrome:
  • It is also called Trisomy-21.
  • It is a chromosomal disorder caused by the presence of all or a part of an extra 21st chromosome.
  • It is associated with impairment of cognitive ability and physical growth and a particular set of facial characteristics.
  • In this syndrome, the person exhibits Mongolism.

Additional Information

• Patau's Syndrome:
  • It is also called Trisomy-13 A syndrome.
  • In this, the patient has an additional copy of autosomal chromosome 13 due to a non-disjunction of chromosomes during meiosis. i
  • Its effects are mental retardation, cut mark in the lip.
• Cri-du-Chat Syndrome:
  • It is a rare genetic disorder due to a missing part of chromosome 5.
  • It is characterized by having a cat-like cry of affected children.
• Klinefelter's Syndrome:
  • It is a condition, in which human males have an extra X-sex chromosome (44 + XXY).
  • Effects are the development of small testicles and reduced fertility.
  • Such persons are sterile males or feminized males with undeveloped testis and some feminine characteristics like enlarged breasts, etc.
  • They may be mentally retarded.

The role of a catalyst-

• The role of a catalyst in a reaction is to lower the activation energy of the reactants.
• Lowering the activation energy increases the rate of the reaction.
• The reaction now proceeds via a low energy path.
• Catalysts and promoters are also used to speed up the process and increase yield.
• For the process of hydrogenation, nickel is used as a catalyst to increase the speed of reaction.
• Unsaturated hydrocarbons add hydrogen in the presence of catalysts such as Nickel and Palladium.
• Through this process, the unsaturated hydrocarbons get converted into saturated ones.
• This process is known as an addition reaction.

Hence, the catalyst used is Nickel and Palladium for adding hydrogen to unsaturated hydrocarbons.