CG PET 2026: Preparation Tips. Historical-cycle information; retain the stated verification limits.
Physics: motion and graphs
A position-time graph and a velocity-time graph encode different quantities. The slope of a position-time graph gives velocity, while the area under a velocity-time graph gives displacement. A straight horizontal segment therefore has different meanings in the two graphs. Read the axis labels before interpreting the shape.
Suppose velocity increases uniformly from 2 metres per second to 10 metres per second over four seconds. The acceleration is 2 metres per second squared. The displacement is the average velocity, 6 metres per second, multiplied by four seconds, giving 24 metres. The trapezoidal area under the velocity-time graph gives the same result.
Distance and displacement are not always equal. If a particle moves three metres east and then one metre west, its distance travelled is four metres while its displacement is two metres east. In graph questions involving a change of direction, signed area gives displacement, while the sum of area magnitudes gives distance.
Use units as part of the solution. A slope calculated from metres divided by seconds cannot be an acceleration. A value with the dimensions of velocity cannot directly answer a question asking for kinetic energy. Dimensional checking is quick and often exposes a wrong formula before a long calculation is completed.
Physics: forces, work and circular motion
Choose the object whose motion is being analysed and draw only the forces acting on it. A common error is to place an action-reaction pair on the same free-body diagram even though the forces act on different objects. Newton's third law does not imply that the net force on each object is zero.
For a 2-kilogram object acted on by a net horizontal force of 6 newtons, the acceleration is 3 metres per second squared. If the problem instead states an applied force of 6 newtons with friction present, the net force must first be found. The word applied cannot be silently replaced with net.
Work depends on the force component along the displacement. A force perpendicular to instantaneous displacement does no work at that instant. In uniform circular motion, the inward resultant changes the direction of velocity while the speed remains constant. That explains how acceleration can be nonzero even when kinetic energy does not change.
For circular motion at radius r and speed v, the required inward acceleration is v squared divided by r. Doubling speed at the same radius requires four times the acceleration. Doubling radius at the same speed halves it. Proportional reasoning like this is often faster and safer than inserting arbitrary numerical values into every option.
Physics: heat, waves and optics
Temperature and heat are different quantities. Temperature describes a thermal state, while heat is energy transferred because of a temperature difference. Two objects at the same temperature can contain different amounts of internal energy because their masses, materials and states differ. Questions using these terms should be read with that distinction in mind.
For a simple heating calculation without a phase change, energy transferred equals mass multiplied by specific heat capacity and temperature change. During a phase change at the relevant conditions, energy can be absorbed without the same temperature rise. Decide whether the problem concerns sensible heating, latent heat or both before combining terms.
A wave carries a disturbance, and its speed equals frequency multiplied by wavelength. When a wave enters a different medium with the source frequency unchanged, a speed change is accompanied by a wavelength change. It is incorrect to assume that all three quantities remain fixed merely because the source is the same.
In optics, draw the principal axis and use a consistent sign convention. A lens question can be solved algebraically, but a rough ray diagram gives a useful check on whether the image should be real or virtual and enlarged or diminished. A negative distance without an interpreted convention is only an algebraic symbol, not a complete physical conclusion.
Physics: circuits and modern ideas
Current is charge flow per unit time. If 12 coulombs pass a cross-section in four seconds, the average current is 3 amperes. This definition helps distinguish current from total charge and from the potential difference driving a circuit. Memorising symbols without quantities makes it easy to substitute the wrong value.
For a resistor obeying Ohm's law under the stated conditions, a potential difference of 12 volts across 4 ohms gives a current of 3 amperes. Its power is 36 watts, obtained from voltage times current. The equivalent expressions involving current squared or voltage squared provide independent arithmetic checks when the resistance is known.
Series and parallel connections should be identified by shared nodes, not by the visual orientation of a drawing. A resistor drawn vertically is not automatically in parallel with another vertical resistor. Redrawing a complicated-looking circuit into a simpler node arrangement can reveal a familiar combination without changing its electrical meaning.
In photon calculations, energy is proportional to frequency and inversely proportional to wavelength. A shorter wavelength means a higher photon energy. Keep the distinction between the energy of one photon and the total energy in a beam containing many photons. Increasing intensity need not mean changing the energy of each photon when the frequency remains fixed.
Chemistry: mole calculations and concentration
Begin a chemical calculation by identifying the amount unit requested. Mass, moles, number of particles and volume are related through different quantities. A balanced equation supplies mole ratios, not a direct rule that all reacting masses are equal. Convert to moles before applying the stoichiometric relationship.
For the reaction in which two moles of hydrogen combine with one mole of oxygen to form two moles of water, three moles of hydrogen require one and a half moles of oxygen. If only one mole of oxygen is available, oxygen limits the reaction and one mole of hydrogen remains under the ideal complete-reaction assumption.
A limiting reagent is determined by the reaction ratio, not simply by identifying the smaller mass or smaller number of moles. Compare how much product each reactant could form. The reactant supporting the smaller product amount is limiting. This method remains reliable when coefficients and molar masses make intuition misleading.
Concentration questions require attention to the denominator. Molarity refers to moles of solute per litre of solution, whereas a mass fraction uses masses. A volume of solvent is not automatically the final solution volume. Read whether the question gives a prepared solution volume or only the starting solvent amount before calculating.
Chemistry: atomic structure and bonding
Atomic number identifies the number of protons, while mass number counts protons and neutrons. Isotopes of an element have the same atomic number but different neutron counts. An ion differs in electron count from the corresponding neutral atom. These three distinctions should be clear before attempting electronic-configuration questions.
Periodic trends are useful patterns, but their explanation matters. Effective nuclear attraction, shell structure and shielding help explain changes in size and ionisation energy. A trend should not be treated as a slogan that automatically overrides every stated species or charge. Comparing an atom with an ion requires more care than comparing two neutral neighbours.
Bond polarity and molecular polarity are also different. A molecule can contain polar bonds whose vector contributions cancel because of the geometry. To judge molecular polarity, identify both the bond dipoles and the molecular shape. Counting electronegative atoms without considering their arrangement can produce the wrong conclusion.
For hybridisation and shape practice, draw the electron-domain arrangement and distinguish bonding pairs from lone pairs where the model requires it. Then identify the molecular geometry asked for. The geometry of all electron domains and the geometry defined by atom positions need not have the same name.
Chemistry: equilibrium and thermodynamics
At dynamic equilibrium, forward and reverse processes continue at equal rates. The amounts of reactants and products remain constant under fixed conditions, but they need not be equal. An option claiming that reactions stop at equilibrium confuses a constant macroscopic composition with the absence of microscopic change.
An equilibrium expression must match the balanced equation and the stated convention. Pure solids and pure liquids are treated differently from variable concentrations or gas pressures in standard expressions. Before substituting numbers, write the expression symbolically. This reduces the chance of carrying an incorrect exponent through a calculation.
A catalyst changes the route and rate of approach to equilibrium without changing the equilibrium constant at a fixed temperature. It does not preferentially improve the final equilibrium amount merely because the desired reaction proceeds faster. Separate kinetic claims from equilibrium claims when comparing answer options.
Thermochemical signs should be attached to the defined system. An exothermic reaction releases heat to the surroundings under the relevant conditions and has a negative enthalpy change in the usual convention. Reversing the reaction reverses the sign. Multiplying the reaction equation by a factor multiplies the enthalpy change by the same factor.
Chemistry: organic reactions and functional groups
Organic revision is more manageable when reactions are organised by changes in functional groups. Identify the starting group, the reagent's role and the product group. A long list of isolated named reactions is difficult to retrieve if the question changes the substrate or asks for an intermediate step.
Distinguish substitution, addition, elimination and oxidation-reduction patterns. In an addition across a multiple bond, atoms or groups are added while the degree of unsaturation decreases in the relevant transformation. In elimination, a small group of atoms is removed and a multiple bond may form. Recognising the broad change helps narrow the possible products.
Isomer questions require a systematic count. Begin with possible carbon skeletons, then place the functional group or multiple bond in distinct positions, removing duplicates caused by symmetry. A structure drawn backwards is not automatically a new isomer. Naming or numbering each candidate consistently helps expose repetitions.
Reaction conditions are part of the question. Temperature, solvent and reagent concentration can influence which pathway is relevant. Do not select a product merely because it appears in a memorised reaction involving the same broad reagent name. Read the full set of conditions and the substrate before committing to an option.
Mathematics: algebra and equations
When solving an equation, keep track of operations that can introduce or remove solutions. Squaring both sides can create extraneous roots, while dividing by an expression can discard cases where that expression equals zero. Substituting candidates into the original equation is a reliable final check.
For example, solving the square root of x plus 1 equal to x minus 1 requires x to be at least 1 before squaring. Squaring gives x plus 1 equal to x squared minus 2x plus 1, so x times x minus 3 equals zero. The candidate zero fails the original domain condition; the valid solution is three.
Quadratic roots can often be handled through their sum and product without solving explicitly. If roots have sum 5 and product 6, the corresponding monic quadratic is x squared minus 5x plus 6. This approach is useful when a question asks for a symmetric expression in the roots rather than the roots individually.
For sequences and series, distinguish a term from a partial sum. In an arithmetic progression with first term 4 and common difference 3, the fifth term is 16, while the sum of the first five terms is 50. A formula can be perfectly remembered but applied to the wrong requested quantity.
Mathematics: functions and calculus
A function's domain is the set of permitted inputs, and its range is the set of resulting outputs. For a real-valued square-root expression, the quantity under the root must be nonnegative. For a rational expression, denominator zeros must be excluded. State these restrictions before simplifying in a way that might hide them.
The derivative gives a local rate of change. For a position function s equal to t cubed minus 3t, velocity is 3t squared minus 3. At t equal to one, velocity is zero, but that does not mean the object has remained at rest throughout its motion. An instantaneous statement should not be stretched into a statement about an entire interval.
A definite integral represents signed accumulation. If part of the graph lies below the axis, the integral over that part is negative. A question asking for total geometric area may require splitting the interval at zeros and adding magnitudes. The phrase area under the curve should therefore be interpreted carefully in the exact problem context.
For maxima and minima on a closed interval, check endpoints as well as interior critical points where appropriate. A derivative-based candidate inside the interval does not automatically give the absolute maximum. Comparing actual function values completes the task and prevents an otherwise correct differentiation from leading to an incomplete answer.
Mathematics: geometry and trigonometry
Coordinate geometry becomes easier when the diagram and equation are used together. For a circle, the centre and radius can often be read after completing squares. An equation with a negative squared radius does not represent an ordinary real circle. This geometric check is faster than continuing to search for points on a nonexistent curve.
The distance between points with coordinates 1, 2 and 4, 6 is five, from the square root of 3 squared plus 4 squared. The slope of the joining line is four thirds. These are different quantities built from the same coordinate differences, so read whether the problem asks for length, direction or an equation.
Trigonometric identities should simplify an expression while preserving its domain. Dividing by sine or cosine assumes that the divisor is nonzero. A solution set can lose valid cases if those zeros are not considered separately. This issue is especially important in equations where a familiar identity tempts a rapid cancellation.
When an angle is specified in degrees, a calculus or numerical formula expecting radians may require conversion. The small-angle approximation for sine uses radians. A remembered approximation applied to a degree value can produce a result wrong by a large factor, even when the arithmetic is internally consistent.
Mathematics: probability, counting and vectors
Counting problems begin with identifying whether order matters and whether repetition is allowed. Choosing three students for an unordered group differs from assigning three distinct roles. The same people can produce several assignments when roles differ. Write a small example if the wording is ambiguous before selecting a permutation or combination formula.
For two independent fair coin tosses, the four equally likely ordered outcomes are heads-heads, heads-tails, tails-heads and tails-tails. Exactly one head occurs in two of them, so the probability is one half. This elementary example demonstrates why counting only the verbal categories zero, one and two heads as equally likely is incorrect.
A vector has magnitude and direction. Adding magnitudes is valid only in special directional arrangements. Two perpendicular vectors of magnitudes three and four have a resultant magnitude five, while opposite collinear vectors of the same magnitudes produce magnitude one. The diagram determines which relationship applies.
For a dot product, the angle between vectors matters through its cosine. Perpendicular nonzero vectors have zero dot product. A zero dot product does not mean either vector must itself be zero. Distinguishing a relation between vectors from a statement about each vector prevents a common conceptual error.
A balanced eight-week preparation plan
In the first week, attempt short diagnostic sets from all three subjects and identify weak foundations. Do not judge readiness from the strongest subject alone. Since Physics, Chemistry and Mathematics each contribute fifty questions, a severe gap in one subject can limit the overall score even when another subject is excellent.
Weeks two and three can focus on rebuilding weak concepts while maintaining daily retrieval from stronger topics. A study day might include one longer problem-solving block, one shorter factual or reaction-revision block and a brief review of previous errors. The exact duration should fit school commitments and concentration rather than imitate someone else's timetable.
Weeks four and five should introduce mixed subject sets and OMR transfer practice. Alternate between untimed concept repair and timed application. If every session is timed, a student may keep rehearsing the same misunderstanding without learning the missing idea. If no session is timed, the student may understand the material but struggle to finish enough questions.
Weeks six and seven should contain full simulations and detailed review. In the final week, reduce the amount of unfamiliar material and concentrate on corrected errors, formulas with conditions, reaction patterns and response-sheet accuracy. A manageable revision list is more useful than a last-minute attempt to reread every chapter from the beginning.
Using a mock test as evidence
After a mock, record the score in each subject, time spent, unanswered items and the reason for each important error. A score increase caused by lucky selections is less reliable than an increase caused by improved understanding. Label guesses during review so that a correct answer does not conceal a knowledge gap.
For each wrong numerical answer, identify the first incorrect step. Reworking the entire solution without locating the failure can feel productive while teaching little. The error may be a wrong model, a sign convention, an arithmetic slip or a unit conversion. Different causes require different corrective exercises.
Create a small repair set for recurring errors. If lens sign conventions are the problem, solve several varied lens questions with diagrams. If mole ratios are the problem, practise limiting-reagent examples with different coefficients. If domain restrictions are the problem, compare equations in which squaring introduces extra candidates.
Repeat a few corrected questions after several days without looking at the solution. Immediate repetition can rely on memory of the answer. Delayed independent solving gives better evidence that the method has been learned. The purpose of the error record is to change later performance, not merely to produce a neat notebook.
Working with an OMR response sheet
Question-number alignment is a separate skill from subject knowledge. Practise skipping an item and returning to it without shifting subsequent responses. A simple routine is to read the question number, identify the selected option and verify the same numbered row before filling. The routine should become automatic through practice.
Use only the marking method permitted in the examination instructions. Do not assume that a crossed-out bubble, a tick or a faint mark will be interpreted as intended. An optical response sheet follows the authority's rules for valid marking, and ambiguous marks may not receive the treatment a candidate expects.
Reserve enough time to check unanswered rows and identity fields. No negative marking makes a final review of genuinely blank valid questions especially worthwhile. However, hurriedly changing already reasoned answers without a specific basis can reduce accuracy. A review should correct identified mistakes rather than respond to vague anxiety.
During the test, keep rough work organised by question number. If a numerical problem is revisited, a labelled calculation is easier to resume than scattered arithmetic. This can save time and reduce the chance of copying an intermediate value into an answer that asks for a later quantity.
A final readiness review
Before the examination, the student should be able to identify the exact paper, explain the marking scheme and carry out an OMR routine without losing question alignment. Subject revision should include mixed problems and corrected errors, rather than only rereading notes. The admit card supplies the final operational instructions for the test session.
Before counselling, the student should know the correct entrance route, the supporting qualification and category documents, and the programmes that are genuinely acceptable. The preference list should be based on academic interest, affordability and verified availability. A separate calendar should show registration, merit review, allotment and reporting deadlines.
Before joining, confirm what has actually been offered and what remains to be completed. A seat is meaningful only if the student can satisfy eligibility, submit the required documents, pay the applicable amount and attend the programme. Keep the final acknowledgement as the record of completion rather than relying on an earlier provisional screen.
For a later admission year, retain the study methods but replace the dates and rules with the new official notification. An article can remain educationally useful while its application calendar becomes historical. That distinction protects students from following an old deadline or a changed process simply because the page title still looks familiar.
