RPSC Senior Grade II (Science) Mock Test - 2 - REET MCQ

• The presence of one element in various structures, having distinctive physical properties, however comparable chemical properties are known as Allotropy. Diverse types of an element are called "Allotropes" or Allotropic Structures. Carbon demonstrates allotropy.
• A fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five to seven atoms.
• They are spheroidal molecules having the composition, C_2n, where n ≥ 30. These carbon allotropes can be prepared by evaporating graphite with a laser. Unlike diamond, fullerenes dissolve in organic solvents. The fullerene C₆₀ is called ‘Buckminster Fullerene’.
• C₆₀ has 60 carbon atoms and 90 bonds, 60 of which are single bonds, and 30 of which are aromatic double bonds. It has 20 hexagonal structures and 12 pentagonal structures. The pentagonal structures contain the single bonds, and the bridging bonds between pentagonal structures contain the double bonds.
• C₆₀ particle has gloriously symmetrical structure. It is an intertwined ring of aromatic framework containing 20 hexagons and 12 pentagons of sp² hybridized C iotas.
• Thus, the Fullerene (C₆₀, an allotrope of carbon) contains 20 hexagons (six membered) rings and 12 pentagons (five membered rings).

Order of repulsive interaction of electron pairs is l.p - l.p > b.p - l.p > b.p - b.p.

Key Points
VSEPR Theory:

• The VSEPR theory is used for predicting the geometrical shapes of molecules.
• It is based on the assumption that electron pairs repel each other and therefore, tend to remain as far apart as possible.
• According to this theory, molecular geometry is determined by repulsions between lone pairs-lone pairs(l.p-l.p), lone pairs-bond pairs(l.p-b.p), and bond pairs-bond pairs(b.p-b.p).
• The shape of the molecule is determined by repulsions between all of the electrons present in the valence shell.
• Electron pairs in the valence shell of the central atom repel each other and align themselves to minimize this repulsion.
• Lone pairs of electrons on the central atom repeal the most. i.e., Lone pair -lone pair repulsion > lone pair-bond pair > bond pair-bond pair.
• The valence shell electron pairs arrange themselves in space as far as possible to minimize mutual repulsion.

Hence the order of repulsive interaction of electron pairs is l.p-l.p > b.p-l.p > b.p-b.p.

Additional Information
Bond Pair - Bond Pair repulsion

• Bonding pairs have a bond between the nucleus of the central atom and the nucleus of a bonding atom,
• therefore, are further away from the nucleus, so they do not repel other electrons as much as lone pairs

Lone pair - Lone pair repulsion

• Lone pairs have the greatest repelling effect because they are closer to the nucleus of the central atom compared to the bonding pairs,
• therefore they repel other lone pairs greater compared to bonding pairs.

Concept:

• Photoperiodism or photoperiod response is a physiological reaction of organisms to the length of day or night.
• It is basically a developmental response of plants to the relative lengths of light and dark periods, for their flowering.
• According to photoperiodism plants can be classified into:

1. Short day plants - These plants give flowers on exposure to photoperiod equal or shorter than their critical day length.
2. Long day plants - These plants give flowers on exposure to photoperiod longer than their critical day length
3. Day-neutral plants - These plants do not require any specific light period for flowering.

Explanation:

• The photoperiod response of the plants is perceived by the leaves. This response is stimulated by a pigment called phytochrome, which is a light-sensitive pigment responsible for flowering.
• phytochromes are a class of photoreceptors that plants use to detect light. They are sensitive to light in the red and far-red regions of the visible spectrum.
• Phytochrome pigment is a proteinaceous pigment found in low concentrations in most plant organs that absorbs red (PR or P660) and far red (PfR or P730) light.

Concept:
The magnetic force experienced by a current-carrying conductor of finite length is given by
F = BIL sin θ
Where,
B = Magnetic flux density of the field
I = Current
L = Length of the conductor perpendicular to the magnetic field
Here angle θ represents the direction of the field and the current.

Explanation:
From the above explanation, we can see that magnetic force exerted by the finite current-carrying conductor is expressed as
F= BIL sin θ
Now the direction of the magnetic field is perpendicular to a current-carrying conductor (i.e., θ = 90°) the above equation can be modified as
F = BIL (∵ sin 90° = 1)
Hence option 1 is correct among all

Concept:

• Malaria is a mosquito-borne, life-threatening disease, caused by various species of the parasitic protozoan namely Plasmodium.
• It is spread exclusively through bites of infected female Anopheles mosquitoes.
• There are five Plasmodium species that cause malaria in humans:
  • P. falciparum
  • P. malariae
  • P. vivax
  • P. ovale
  • P. knowlesi
• The symptoms of malaria are observed within 7 to 18 days of being infected. The common symptoms are-
  • Fever, fatigue, headaches, chills, and vomiting are the first observable symptoms.
  • Diarrhoea, anemia, and muscle pain
  • Profuse sweating, convulsions, and blood in the stool.
  • In severe cases, it can lead to seizures, coma, and eventually, death.

Key Points

• Malarial parasite is digenetic in nature, as its life cycle completes in two hosts.
• Mosquitoes are the definitive or primary hosts for the parasites, while humans and other vertebrates are the intermediate or secondary hosts.
• In the definitive or primary hosts, the parasites undergo sexual reproduction.
• An intermediate host is a host that harbors the non-sexual reproduction of the parasite.
• The intermediate host of malaria parasites is man.
• The first is when enters the human body as sporozoites from the body of the mosquito which grows as merozoites in the human bloodstream and moves on as gametocytes back to the body of the mosquito.

The life cycle of Malaria parasites-

• Plasmodium parasite exists in the form of a motile sporozoite.
• The female Anopheles mosquito transmits the sporozoites into the hosts by biting.
• Sporozoites initially multiply within the liver, by damaging the liver and rupturing the blood cells in the body.
• They grow as merozoites in the human bloodstream.
• Plasmodium reproduces asexually in the RBCs and thus releasing more parasites to infect more cells.
• The rupture of RBCs releases a toxin called hemozoin, and due to this infected people experience chills.
• When the female Anopheles mosquito bites an infected person the parasites move on as gametocytes back to the mosquito's body to complete the sexual phase.
• Inside Anopheles's body, the actual development and maturation of the parasite happen.
• The life cycle of the malaria parasite is showing belong schematically-

Additional Information

• Female Anopheles-
  • Female Anopheles mosquito is the carrier or vector for Plasmodium species.
  • ​​It is the definitive host of the parasites.
  • In Anopheles, the Plasmodium species undergo sexual reproduction.
• Culex-
  • ​It is a genus of mosquitoes.
  • Culex is an important vector for several severe diseases such as filariasis, Japanese encephalitis, West Nile virus, avian malaria, etc.
• Tse-tse fly-
  • It spreads infections with protozoan parasites belonging to the genus Trypanosoma. ​
  • It causes African sleeping sickness.

Hence the correct option is (1) Man.

Concept:

• Simple harmonic motion (SHM): It is a special type of oscillation in which the particle oscillates on a straight line, the acceleration of the particle is always directed towards a fixed point on the line and its magnitude is proportional to the displacement of the particle from this point.
  • The displacement and the velocity of a particle executing a simple harmonic motion are given by x = A sin(ωt) and v = A ω cos(ωt)
• Composition of two SHM: When two waves going in the same direction with amplitude A₁ and A₂ then the resultant amplitude is
  • [δ =phase angle between them]
  • If δ = 0, then,
  • If δ = π then,
  • As the amplitude is always positive, we can write

Calculation:

Given - A₁ = 2 cm, A₂ = 2 cm and δ = π/3

• The resultant amplitude is given by

• Adaptive radiation is a process of evolution of different species in a given geographical area.
• It starts from an ancestral stock and radiating or moving to other habitats.
• It was first shown by Darwin while he studied the species of finches in the Galapagos islands.
• There were several species of finches that had diverged from the original seed-eating species.
• Competing with the same resources on the island allowed them to adopt with new beak features that reduced competition for survival.
• The feeding habit of Darwin's finches ranged from seeds to insects and many more.
• Similar example can be given for Australian marsupials and Australian placental mammals, that evolved within the continental island from an ancestral stock.
• The Australian placental mammals also show similarities with a corresponding marsupial. E.g.-Anteater and Numbat.

Additional Information

• Moths in England exemplify natural selection.
• A change was observed in the population of peppermoths of England after industrialization.
• Before industrialization, white-winged moths were more prevalent on the trees that were covered with whitish lichen, which grew in the absence of pollution.
• Post-industrialization, the trees became covered with soot and smoke, exposing the white-winged moths to predators.
• Here, the dark-winged or melanized moths survived better and hence became prevalent.
• In rural areas, however, the white-winged moths prevailed.
• This shows a directional selection in favour of the dark-winged moths in industrial are.

The correct answer is first order reaction.

Key Points

• A first order reaction is one where the rate of reaction is directly proportional to the concentration of one of the reactants.
• The rate law for a first order reaction is given by: Rate = k[A], where k is the rate constant and [A] is the concentration of the reactant.
• In a first order reaction, the half-life is constant and does not depend on the initial concentration of the reactant.
• Examples of first order reactions include radioactive decay and some types of chemical decompositions.

Additional Information

• Zero Order Reaction
  • A zero order reaction is one where the rate of reaction is independent of the concentration of the reactants.
  • The rate law for a zero order reaction is given by: Rate = k, where k is the rate constant.
  • In a zero order reaction, the rate of reaction remains constant until the reactant is exhausted.
• Second Order Reaction
  • A second order reaction is one where the rate of reaction is proportional to the square of the concentration of one reactant or the product of the concentrations of two reactants.
  • The rate law for a second order reaction is given by: Rate = k[A]^2 or Rate = k[A][B], where k is the rate constant and [A], [B] are the concentrations of the reactants.
  • The half-life of a second order reaction is inversely proportional to the initial concentration of the reactant.
• Third Order Reaction
  • A third order reaction is one where the rate of reaction is proportional to the cube of the concentration of one reactant or the product of the concentrations of three reactants.
  • The rate law for a third order reaction is given by: Rate = k[A]^3 or Rate = k[A][B][C], where k is the rate constant and [A], [B], [C] are the concentrations of the reactants.
  • Third order reactions are less common compared to first and second order reactions.

Taxonomy was a word used by Bloom to describe the classification of educational objectives. The taxonomy contains three domains: Cognitive, affective and psychomotor domain. The psychomotor domain is the third domain in Bloom’s taxonomy.

Important Points
The third type of learning described by Bloom is psychomotor learning. This kind of learning involves motor, muscular activities. Just as in cognitive and affective learning, - psychomotor learning also occurs in combination with the other two types of learning. It is demonstrated by physical skills which are acquired through practise in response to cues and stimuli from the surroundings. Riding a bicycle, driving a car, playing the tabla, kicking a ball, hitting a ball with a bat, typing, and drawing a sketch of a building are some of the examples of psychomotor learning.

Key Points
Levels of the psychomotor domain are:

• Imitation: This is the lowest or first level of the objectives in the psychomotor domain. When children are exposed to observable situations, they attempt to imitate the action.
• Manipulation: This is the ability to perform certain actions by following instructions and practising. At this level children are able to differentiate between different sets of the act and are able to select the required action.
• Precision: At this level, the proficiency of performance reaches a high level of refinement in producing a given act. The act becomes refined and more exact. At this level, children reproduce an act without instruction or a model. They are able to introduce variations according to the requirements of situations.
• Articulation: This is about coordinating a series of actions, accomplishing harmony and internal consistency among different acts.
• Naturalization: Complex performance becomes natural at this level without using much psychic energy. The act is done without much conscious thinking. The act gas automatised and is carried out unconsciously.

Thus from the above-mentioned points, it is clear that the first level of the psychomotor domain is imitation.

Concept:

Nucleophile and Electrophile

• Nucleophile: A nucleophile is an electron-rich species that donates a pair of electrons to form a bond with an electrophile. Nucleophiles typically have a negative charge or lone pairs of electrons.
• Electrophile: An electrophile is an electron-deficient species that accepts a pair of electrons from a nucleophile to form a bond.

Explanation:

• (NO₂⁺): The nitronium ion (NO₂⁺) is positively charged and electron-deficient, meaning it acts as an electrophile, not a nucleophile.
• (:CCl₂): This is a carbene, a neutral species with an empty p-orbital. Carbenes tend to act as electrophiles rather than nucleophiles, despite having lone pairs of electrons.
• (CH₃⁺): The methyl cation (CH₃⁺) is positively charged and electron-deficient, making it an electrophile, not a nucleophile.
• (CN^-): The cyanide ion (CN^-) is negatively charged and has a lone pair of electrons on the carbon atom, making it an excellent nucleophile because it can donate electrons easily.

​Conclusion:
The correct answer is: Option 4 (CN^-).

The geometry of four sp³ hybrid orbitals is tetrahedral.

Key Points

Hybridization:

• The atomic orbitals s, p, d, f of the central atom having compatible energies mix up.
• This leads to the formation of new hybrid orbitals which have now different energies, shapes, and orientations than the component atomic orbitals.
• The number of hybrid orbitals is equal to atomic orbitals mixing.
• After the formation of hybrid orbitals, they overlap with atomic orbitals of suitable side atoms and leads to the formation of covalent chemical bonds.
• The formula for calculating hybridization - H = ½ (V + M -C + A)
• Where V = number of valence electrons on the central atom. M = No. Of monovalent atoms C = cationic charge A = anionic charge.

Few types of hybridization, their modes of mixing, and the geometry of molecules are-

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. Science Teachers help middle and high school learners understand scientific phenomena.

Key Points

The Role of a Science Teacher:

• Design curriculum as per the needs of the students.
• Instruct students on the proper use of equipment, materials, aids, and textbooks.
• Provide a rich variety of learning experiences to learners.
• Establishing classroom, lab, and field trip rules and regulations and ensuring that all students understand what is expected of them.
• Grading papers, updating records, and handling various administrative tasks.
• Creating an environment where students feel comfortable asking questions.
• Participating in other school activities and regularly communicating with parents.
• Drawing up suitable assessments and delivering helpful feedback to students, parents, and other teachers.

Hence, from the above-mentioned points, it becomes clear that the role of a science teacher should be to provide rich variety of learning experiences to learners.

Concept:

• Centre of gravity: The Centre of gravity in a body is a point where total gravitational torque on the body is zero.
  • It is a point where the weight of the body acts.
    

Explanation:
If  is the position vector of a particle mass mi in a body, then the centre of gravity is located such that the total torque (τ) on it due to forces of gravity on all the particles is zero.
(i)
where g is the acceleration due to gravity.
As is non zero we may rewrite (i) as:
(ii)

Hence option 2) is correct.

Team teaching involves two or more teachers working together to plan, deliver, and assess instruction. This collaborative approach is intended to enhance the learning experience for students by leveraging the strengths and expertise of multiple educators.

Key Points

• In team teaching, teachers actively collaborate. They may share responsibilities such as lesson planning, instructional delivery, and assessment. This collaborative effort often allows for a more comprehensive and varied approach to teaching.
• Team teaching allows educators to bring their strengths and expertise into the learning environment. For example, one teacher might specialize in a particular subject area, while another may excel in instructional strategies or classroom management. The combination of these strengths can benefit the overall learning experience.
• Team teaching can also serve as a form of professional development for teachers. They can learn from each other, share innovative teaching practices, and refine their skills through ongoing collaboration.

Thus, it is concluded that Team teaching is working together of two or more teachers.

Concept:

​Electromagnetic waves:
Electromagnetic waves are formed when an electric field comes in contact with a magnetic field. They are hence known as 'electromagnetic waves. The electric field and magnetic field of an electromagnetic wave are perpendiculars (at right angles) to each other.

→ When moving through the electric field and magnetic field in mutually perpendicular directions:
Due to the electric field Force is always in the direction of the electric field and force

where F is the force due to the electric field, q is the charge, and E is the electric field.
→ When the direction of the velocity of the charged particle is perpendicular to the magnetic field: Magnetic force is always perpendicular to velocity and magnetic field by Right-Hand Rule.

where F is the force due to the magnetic field, q is the charge, v is the velocity and B is the magnetic field.

Calculation:
Given:
Frequency of wave = 100 MHz (along x- direction) = 100 MHz
Magnetic Field, = 2.0 x 10-8 T.
(where, is unit vector along z-direction)
Speed of light c= = 3 x 108 m/s
= ?
Hence, the electric field at the point is calculated as:
(Dir. of the wave) ||

Hence, Option (2) is the correct answer.

Osmotic pressure can be defined as the minimum pressure that must be applied to a solution to halt the flow of solvent molecules through a semipermeable membrane. It is a colligative property and is dependent on the concentration of solute particles in the solution.

It can be calculated with the formula π = iCRT
Where, π = the osmotic pressure
→ i = Van’t Hoff Factor (value = number of dissociated ions)
→ C = molar concentration of the solute in the solution
→ R = universal gas constant, T = temperature
In the above question, RT will remain constant and whatever the difference will be because of i × C

Option 1: 200 mL of 2 M NaCl solution (i = 2, for NaCl)
π = 2 × concentration of NaCl × RT
π = 2 × 2 × RT → π = 4 RT

Option 2: 200 mL of 1 M glucose solution (i = 1 as it is non electrolyte)
→ π = 1 × 1 × RT
→ π = 1 × 1 × RT → π = RT

Option 3: 200 mL of 2 M urea solution (i = 1 as it is non electrolyte)
→ π = 2M × 1 × RT
→ π = 2 × 1 × RT → π = 2 × RT
∴ Glucose solution has minimum osmotic pressure.

Concept:

Collision-

• The meaning of the term ‘collision’ in our everyday life ‘striking’, in physics it does not necessarily mean one particle striking against another.
• Indeed two particles may not even touch each other and may still be said to collide.
• A collision occurs when two bodies come in direct contact with each other.
• In this event, two or more bodies exert forces on each other in about a relatively short time.
• The collision is in fact a redistribution of the total momentum of the particles

Types of Collision-
The law of conservation of momentum holds true in the collision between two masses but,
there may be some collisions in which Kinetic Energy is not conserved.
Depending on energy conservation, Collisions are basically of two types:
1. Elastic Collision: ​

• In the elastic collision total momentum, total energy, and total kinetic energy are conserved.
• Although, the total mechanical energy is not converted into any other form of energy as the forces involved in the short interaction are conserved in nature.

2. Inelastic Collision:

• In the inelastic collision, the objects stick to each other or move in the same direction.
• The total kinetic energy of the system containing colliding objects is not conserved but the total momentum and energy are conserved.
• During Inelastic collision, the energy is transformed into other energy forms like heat and light.

Calculation:
Mass of the ball, m = 2 kg
Kinetic energy before the collision, K_i = 100 J
Let the velocity of the ball after a direct collision with a rigid wall be v.
As the collision is elastic in nature, so the kinetic energy of the ball will remain conserve.
i.e. K_i = K_f

∴ v = 10m/s
Hence, option-3 is correct

A question paper is set to check the knowledge acquired by the students and to know the achievement of students. The students have to specifically demonstrate the knowledge and information acquired by them. A good question paper must be purposeful, valid, relevant, concise, and objective.

Key Points

Blueprint:

• The term 'Blue Print' is derived from the domain of architecture which means 'detailed plan of action'. Here, in education it deals with the detailed plan of the question paper or it is also known as test specification providing examinations strategy of an institution at a glance.
  • It is a three-dimensional chart which is the basic outline of the test that is going to be conducted.
  • It shows the placement of each question with respect to the objective and the content area that it tests.
  • It must follow the respective weightage to all the units, lessons, objectives in the subject matter as mentioned in the syllabus.
  • The teacher considers it as a guide while making question papers which eases the procedure of setting the question papers.​
  • It is useful to prepare a blueprint so that the test maker could know which question will test which objective and how many marks it would carry.
  • A test constructor should have good knowledge of the subject. It is very important to decide the content of the test first, and then proceed accordingly.
  • The test items should be clear, unambiguous, and according to the objectives. Different types of items - essay, short-answer, and objective types - should be written out in sufficient numbers.
  • It is necessary to analyze the objectives of the course and decide which objectives are to be tested and in what properties. For this marks are allotted to each objective to be tested based on their importance.
• The example of a blueprint table is shown below:
  

Hence, it could be concluded that the difficulty level of questions is not available from the blueprint table of a question paper.

The correct answer is 6.

Key Points

• Let's denote the oxidation number of sulfur as 'x'.
• In H₂S₂O₇:
• Hydrogen (H) has an oxidation number of +1.
• Oxygen (O) has an oxidation number of -2.
• The overall charge of the molecule is 0.
• So, we can set up the equation:
• 2(+1) + 2(x) + 7(-2) = 0
• Simplifying:
• 2 + 2x - 14 = 0
• 2x = 12
• x = +6
• Therefore, the oxidation number of sulfur (S) in H₂S₂O₇ is +6.

• Diffusion refers to the process in which a solid, liquid, or gas moves from a higher concentration to a lower concentration medium to attain equilibrium.
• In diffusion the molecules of one substance mix with the molecule of the other substance.
• Diffusion is of two types -
  • Simple diffusion - In simple diffusion, the particles move through the semipermeable membrane without any assistance from carrier molecules.
  • Facilitated diffusion - is the movement of molecules from a higher concentration to a lower concentration with the help of a transporter or a carrier molecule across the cell membrane.
• Diffusion always tends to equalize the concentration of the solutions.

Important Points

Option 1- CORRECT

• The diffusing molecules move randomly, they do not follow any direction.
• Molecules are moved from the lower concentration region to the higher region.
• It tends to uniformly distribute substances.

Option 2 - CORRECT

• The rate of diffusion is affected by the density of the medium through which they move.
• When the density of the medium is high then the rate of diffusion increases and vice versa.

Option 3 - INCORRECT

• The direction of diffusion of one substance is not dependent on the movement of another substance.
• It depends on the concentration gradient of the medium.
• As the particles move from the lower concentration region to the higher.

Option 4 - CORRECT

• Kinetic energy plays important role in the movement of molecules.
• Kinetic energy increases the motion of the particles and lower kinetic energy decreases the motion of the particles.
• The kinetic energy of the diffusing molecules increases when temperature and pressure are increased.

Hence the correct answer is option (3).

Concept:

• Simple harmonic motion occurs when the restoring force is directly proportional to the displacement from equilibrium.

F α -x

Where F = force and x = the displacement from equilibrium.

• For a simple harmonic motion equation of acceleration

where a is the acceleration ω is the angular frequency and x is the displacement.

Explanation:

• For a simple harmonic motion equation of acceleration

where a is the acceleration ω is the angular frequency and x is the displacement.

• The negative sign indicates that acceleration is opposite to the direction of displacement.

So the correct answer is option 1.

Correct option:2

Concept:-

Modulation:- It is the process of attaching a low-frequency base-band signal to the high-frequency carrier wave in order to get high frequency modulated signal for its effective transmission.

There are basically three kinds of modulations:-
1. Amplitude modulation (AM)
2. Frequency modulation (FM) and
3. Pulse modulation (PM)

Explanation:-
Frequency modulation (FM): In this kind of modulation the frequency of the carrier signals is modified according to the instantaneous amplitude of the baseband signal in frequency modulation.

Here the phase and the amplitude of the carrier signal remain constant.
An increase in the amplitude of the base-band signal increases the frequency of the carrier and vice-versa.

In FM (Amplitude modulation) the Amplitude and the phase of the carrier signal remain constant.
i.e. Both the Amplitude and frequency of the modulated wave are identical to that of a carrier wave.
Suppose the carrier wave is written as-

Base-band signal wave is written as-

So the wave equation of AM wave is given by-
or

Here, the only frequency gets modify while amplitude (A_c)remains identical to that of the carrier wave signal.
Therefore, Out of all the given option-2 is correct.

Additional Information:
Amplitude modulation (AM): In this kind of modulation the amplitude of the carrier signal is modified according to the instantaneous amplitude of the base-band signal.

Phase Modulation (PM): If the instantaneous amplitude of the baseband signal modifies the phase of the carrier signal keeping the frequency and amplitude constant is called Phase modulation and this modulation is used to generate frequency-modulated signals.

It is similar to frequency modulation except that in this modulation the phase of the carrier is varied instead of varying frequency.

Concept:

• The magnetic Declination (θ): It is the angle between geographic and magnetic meridian planes.
  • Declination at a place is expressed at θ° E or θ° W depending upon whether the north pole of the compass needle lies to the east or to the west of the geographical axis.
• The angle of inclination or Dip (Φ): It is the angle between the direction of the intensity of the total magnetic field of earth and a horizontal line in the magnetic meridian.

The angle of dip is given by:
ϕ = tan^-1(B_V / B_H)
where B_V​ = vertical component of earth's magnetic field and B_H​ = horizontal components of earth's magnetic field.

Concept:

Crystal Field Theory and Magnetic Properties

• In octahedral complexes, strong field ligands like L cause a large splitting of the d-orbitals (Δ₀), forcing electrons to pair up in the lower-energy t_2g orbitals.
• For a complex with five d-electrons and strong field ligands, the electrons will first fill the lower t_2g orbitals before occupying the higher eg orbitals.
• This leads to pairing of electrons, reducing the number of unpaired electrons.

Explanation:

• For a complex with five d-electrons and strong field ligands, the electrons will occupy the t_2g orbitals first.
• Four electrons will pair in the t_2g orbitals, leaving 1 unpaired electron.

Conclusion:

The correct answer is: 1 unpaired electron.

The Regional College of Education, Mysore (R.C.E.M) developed its system known as the R.C.E.M. In this system, mental skills are also considered very important. It accepted Bloom's Taxonomy as its foundation. Bloom has divided the cognitive objectives into six objectives, but the R.C.M.E. approach has transformed the six cognitive goals of Bloom into only four objectives. Bloom’s three most recent goals, namely analysis, synthesis, and evaluation have been termed ‘creativity, in the R.C.E.M. system. All mental abilities, involved in these four objectives, are grouped into 17 categories. Thus, we see that all human learning activities are divided into 17 mental skills.

Following are some examples of writing objectives in behavioral terms according to R.C.E.M. System-

1. Cognitive Objective: The pupils can recall the definition of the term 'Motivation'.
2. Understanding Objective: The pupils can differentiate teaching and training.

Additional InformationR.C.E.M. Approach: It consists of teaching objectives and learning experiences. The question-teaching is considered an interactive process. It is commonly known as the R.C.E.M. approach to lesson planning. This approach was developed in the Regional College of Education Mysore. It consists of three aspects-

• Input – This aspect is concerned with the identification of objectives. The input may also be termed as expected behavioral outcomes (EBOs). These objectives are broadly classified as knowledge, understanding, application, and creativity.
• Process – This aspect is concerned with the presentation of content and learning experiences. The main focus is to create the learning situations for providing an appropriate learning experience to the learners.
• Outcome – This aspect is concerned with the real learning outcomes (RLOs).

Concept:

• Periodic motion: A motion that repeats itself after a period is called periodic motion.

The equation of Periodic motion is given by:
f(t) = A sin(ωt+ϕ)
where f(t) is the position at any time t, A is amplitude, t is time, and ω is the angular frequency.

• Amplitude (A): The maximum displacement from the mean position is called amplitude.
• frequency (f): The no. of oscillations in one second is called frequency.
• Time period (T): The time is taken to complete one oscillation is called time period.

Angular frequency (ω) is given by:
ω = 2π/T
where T is the time period.

Calculation:
Given equation is f(t) = A cos(ωt + φ)
comparing with standard equation angular frequency is ω.
Angular frequency (ω) is given by:
ω = 2π/T
T = 2π/ω
The time period is 2π/ω
So the correct answer is option 3.

For redox change

n-factor = 5
n_eq = nmol × n-factor
= 1 × 5
= 5
Charge required in Faraday = Number of n_eq
= 5 F

Concept:

Angular velocity (ω): The rate of change of angular displacement is called angular velocity.

• Mathematically,
• It is a vector quantity whose unit is radian/sec.

Angular acceleration (α): The rate of change of angular velocity is called angular acceleration.

• Mathematically,
• It is a vector quantity whose unit is radian/sec².

The below table represents Kinematic equation for translation motion and rotational motion
And if angular acceleration is constant then, it follows the rule similarly to equations of motion.
Then ω, α and θ are related as:

Calculation:
Given that,
Number of revolutions per min = 12 rev/sec
Initial angular velocity, ω₀ = 12rev/sec
Constant opposing torque acting on it for 4 sec
Final angular velocity, ω = 0 rev/sec
Thus, by using the kinematic equation we can use relation, ω = ω₀ + αt
Hence the rate of deceleration of wheel will be given as

Here negative sign shows that object is decelerating because of opposing torque

The correct answer is option 4.

Concept:

• Cellular respiration is a catabolic reaction taking place in the cells and the Krebs cycle is a part of Cellular Respiration
• Cellular respiration has four parts:
  1. Glycolysis - Partial oxidation of a glucose molecule to form 2 molecules of pyruvate in the cytosol.
  2. Formation of Acetyl CoA - Pyruvate enters the mitochondrial matrix and oxidative decarboxylation to form two molecules of Acetyl CoA.
  3. Krebs cycle (TCA cycle or Citric Acid Cycle)
  4. Electron Transport System and Oxidative Phosphorylation: In the inner membrane of mitochondria, ATP is generated when electrons are transferred from the energy-rich molecules like NADH and FADH2 (produced in earlier steps) to molecular O2 by a series of electron carriers.

Explanation:
Let us see Kerb's cycle:
Formation of citric acid

• The tricarboxylic acid (TCA) cycle is known as Kerb's cycle.
• It begins with the condensation of the acetyl group with oxaloacetic acid and water to form citric acid in presence of the enzyme citrate synthase.

Substrate level phosphorylation and formation of a-ketoglutaric acid and succinyl CoA

• Further, two steps of decarboxylation occur leading to the formation of a-ketoglutaric acid and succinyl CoA.
• Succinyl CoA is converted into succinic acid and a molecule of guanosine triphosphate (GTP) is formed. This is called substrate-level phosphorylation.

• In other reactions, GTP is converted into GDP and ATP is synthesised from ADP.

Formation of oxaloacetic acid

• In the remaining steps of the citric acid cycle, succinyl CoA is oxidised to OAA for the cycle to continue.
• In a single turn of Kerb's cycle, a single GTP molecule is synthesised and substrate level phosphorylation occurs only once.
• At three places in the cycle, NAD⁺ is reduced to NADH + H⁺ and at one place FAD⁺ is reduced to FADH₂.

So, the correct answer is option 4.