CBSE Class 10 Mock Test 2027: Free 10th Board Test Series

AMBER CALLOUT BOX: 4 Big Traps in Competitor Class 10 Mock Tests and Sample Paper Websites

• (1) Referred to as a "Full 80-Mark Board Mock": Although many coaching platforms provide a short 20-mark multiple-choice quiz and call it a full board examination, they entirely overlook the 60-mark Step-Marked Subjective, Case-Study (4 marks), and Map (5 marks) sections. Our mock exam series includes instant auto-grading for the multiple-choice questions together with an official CBSE Step-Marking Self-Grader for the descriptive answers!
• (2) When it comes to questions on chapters that have been deleted, various free PDF websites ask questions about topics which have been removed from the syllabus (for example, the Periodic Classification of Elements, the Electric Motor and Generator, Euclid's Division Lemma, and Constructions). All the questions in this case have been screened to ensure they conform to the rationalised NCERT syllabus for 2026–27.
• (3) Failing to match the Science 39-question grouping and the distinction between Maths Standard (041) and Maths Basic (241): Generic mock exams do not reflect the official 2026-27 Science SQP structure, which groups the 39 required questions into Biology (30M), Chemistry (25M), and Physics (25M), and they also do not separate Maths Standard (041) from Maths Basic (241).
• (4) Misunderstandings about the 2027 two-board-exam policy: There is a large number of rumours about the board exams. The fact is that the First Board Exam (in February–March 2027) is 100% mandatory. The Second Board Exam (in May 2027) is strictly an optional opportunity to improve your score in up to three main subjects, with your highest score being retained.

After you submit any mock test, our AI Weak-Area Report begins to work. First, it distinguishes between Concept Gaps (a wrong standard MCQ), Competency/Application Gaps (failing a 4-mark case study) and Step-Writing Gaps (losing half marks in 3-mark or 5-mark questions because you omitted formulas, SI units or chemical state symbols). Second, it identifies your specific rate of falling into the Assertion-Reason trap. Finally, the engine automatically creates a personalised 20-minute corrective exercise from either Tab 2 or Tab 4 to address those exact weaknesses before your next pre-board mock.

Table 1: Eliminating 1-Mark MCQs and Assertion-Reason questions – 0.00 penalty
If you leave any of the 20 MCQs in Section A blank, you will lose the mark completely. Since there is no negative marking, it is always mathematically better to make an educated guess. To answer Assertion-Reason questions with 95% accuracy, use the three-step 'truth then because' method: first, read the Assertion (A) by itself to check whether it is true; next, read the Reason (R) by itself to check if it is true; finally, join the two statements using the word 'BECAUSE'. If the resulting sentence makes perfect logical sense, choose Option A; if it does not, select Option B.

Table 2: CBSE's official step-marking scheme for 3-mark and 5-mark questions
Even if your final calculation is wrong, the examiners give partial credit for each step. You should therefore practise showing all the necessary steps.

• For a 3-mark Physics or Maths question: 0.5 marks are awarded for writing down the 'Given' values and the correct formula; another 1.0 mark is given for correct substitution; a further 1.0 mark is given for the calculation; and the final 0.5 marks are awarded only if the final answer is correct and includes the appropriate SI unit.
• For a 3-mark Chemistry question: you earn 1.0 mark for writing the balanced skeletal equation; you get 1.0 mark for adding the physical states (s, l, g, aq) and the reaction conditions above the arrow; and the last 1.0 mark is given for stating the observation or the colour of the precipitate.

Q1. (Chemistry – Redox/pH case-application MCQ) A student adds dilute hydrochloric acid to copper oxide powder in a beaker. What change will be observed and what is the nature of the newly formed compound?
A. The solution becomes colorless. Copper chloride is acidic.
B. The solution becomes blue-green; copper(II) chloride is a basic salt.
C. The solution changes to blue-green and copper(II) chloride is produced, which shows that metallic oxides are basic in character. [Correct]
D. The solution turns red and copper(II) chloride is produced, which shows that metallic oxides are acidic.

Option (Correct) → Reason: C. The solution turns blue-green and copper(II) chloride is formed, which proves that metallic oxides are basic in nature. The reaction between a metallic oxide (CuO) and an acid (HCl) produces salt (CuCl₂, which is blue-green) and water, resembling a neutralisation reaction and thus demonstrating the basic character of metallic oxides.
Option (Incorrect) → Reason: A. The solution does not remain colourless; it turns blue-green.
Option (Incorrect) → Reason: B. Copper(II) chloride is a normal salt formed in this reaction, but it is the conclusion regarding the oxide that is important.
Option (Incorrect) → Reason: D. Metallic oxides are basic, not acidic.
Hint: Remember the characteristic blue-green colour of aqueous copper(II) chloride.

Q2. (Biology Life Processes Competency MCQ) In an experiment to show that carbon dioxide is necessary for photosynthesis, potassium hydroxide (KOH) is placed in a watch glass inside one of the bell jars. What is the specific function of KOH here?
A. So that oxygen may be released for the plant's respiration
B. To draw carbon dioxide from the air within the enclosure [Correct]
C. To give moisture to the plant leaves.
D. To take in the extra oxygen which is produced as a result of photosynthesis

Correct option → Reason: B. It absorbs carbon dioxide from the air inside the container. KOH has the ability to absorb CO₂. If the plant is deprived of carbon dioxide, photosynthesis will stop and as a result the leaf will be negative for starch when tested with iodine.
Option (Incorrect) → reason: A. KOH does not give off oxygen.
Option (Incorrect) → reason: C. It is a desiccant and absorbs water, but its main function in the experiment is the absorption of carbon dioxide.
Option (Incorrect) → reason: D. It does not absorb oxygen.
Hint: The plant cannot produce starch if there is no carbon dioxide.

Q3. (Physics Electricity Numerical MCQ) Two resistors of 10 Ω and 20 Ω are connected in series with a 6 V battery. What is the potential difference across the 10 Ω resistor?
A. 2 V [Correct]
B. 3 V
C. 4 V
D. 6 V

Option (Correct) -> Reason: A. 2 V. First, calculate the total resistance $R_s = 10 + 20 = 30 \, \Omega$. Then find the current $I = V/R = 6/30 = 0.2 \, A$. The voltage across the $10 \, \Omega$ resistor is $V_1 = I \times R_1 = 0.2 \times 10 = 2 \, V$.
Option (Incorrect) -> Reason: B. This would be the voltage if the resistors were equal.
Option (Incorrect) -> Reason: C. This is the voltage across the $20 \, \Omega$ resistor ($0.2 \times 20 = 4 \, V$).
Option (Incorrect) -> Reason: D. This is the total source voltage.
Hint: In a series circuit the current remains constant while the voltage divides in proportion to the resistance.

Q4. (Science Assertion-Reason Trap Question) Read the statements carefully.
Assertion (A): Veins have thin walls and possess valves.
Reason (R): Blood flows in veins under high pressure, and the valves prevent its backflow.
A. A and R are both true, and R is the correct explanation of A.
B. Both A and R are true, but R does not provide the correct explanation for A.
C. A is true while R is false. [Correct]
D. A is false while R is true.

The correct option is C. because A is true but R is false; it is true that veins have thin walls and valves, but the blood in veins flows under very low pressure, which is the reason why valves are necessary to prevent backflow.
The option A is incorrect because the reason statement includes a factual error about high pressure.
The option B is incorrect since R is factually false.
The option D is incorrect because A is actually true.
Hint: arteries are subjected to high pressure and veins to low pressure.

Question 5. (Algebra AP Competency MCQ) The fourth term of an arithmetic progression is 14 and its twelfth term is 70. What is the first term?
A. -10
B. -7 [Correct]
C. 7
D. 10

Correct option -> Reason: B. -7. By using the formula $a_n = a + (n-1)d$, we obtain Equation 1: $a + 3d = 14$ and Equation 2: $a + 11d = 70$. When Equation 2 is subtracted from Equation 1, the result is $8d = 56$, so $d = 7$. Substituting this value of $d$ into Equation 1 gives $a + 3(7) = 14$, or $a + 21 = 14$, which means that $a = -7$.
Incorrect option -> Reason: A. There was a miscalculation when carrying out the subtraction.
Incorrect option -> Reason: C. The negative sign was dropped during transposition.
Incorrect option -> Reason: D. It is a basic arithmetic error.
Hint: Form a system of linear equations by using the standard AP formula.

Question 6. (Multiple choice question on the application of trigonometry) When the altitude of the sun changes from 45 degrees to 30 degrees, the shadow of a vertical tower upon level ground becomes 10 metres longer. Find the height of the tower. (Use √3 = 1.732)
A. 13.66 m [Correct]
B. 10 m
C. 15.25 m
D. 5 m

Option (Correct) -> Reason: A. 13.66 m. Let the height be $h$ and the initial shadow be $x$. Since $\tan(45^\circ) = h/x$, it follows that $1 = h/x$ and therefore $h = x$. When the angle is $30^\circ$, the shadow length is $x + 10$. Then $\tan(30^\circ) = h / (x+10)$, which gives $1/\sqrt{3} = h / (h+10)$. Hence, $h\sqrt{3} = h + 10$, so $h(\sqrt{3}-1) = 10$ and thus $h = 10 / (\sqrt{3}-1)$. By rationalising the denominator, $h = 10(\sqrt{3}+1) / 2 = 5(1.732 + 1) = 5 \times 2.732 = 13.66$ m.
Option (Incorrect) -> Reason: B. The tangent formula was not applied correctly.
Option (Incorrect) -> Reason: C. An arithmetic error occurred during rationalisation.
Option (Incorrect) -> Reason: D. Divided by 2 without adding the $\sqrt{3}$ value.
Hint: Draw two right-angled triangles that have the same vertical height $h$.

Q7. (Statistics Assertion-Reason Question) Read the statements carefully.
Assertion (A): The median of the first 9 natural numbers is 5.
Reason (R): When the number of observations is odd ($n$), the median is the value of the $((n+1)/2)^{\text{th}}$ observation.

A. A and R are both true, and R is the correct explanation of A. [Correct]
B. Both A and R are true, but R does not provide the correct explanation for A.
C. A is true while R is false.
D. A is false but R is true.

The correct option is A because both A and R are true and R is the correct explanation of A. The first nine natural numbers are from 1 to 9. Since n equals 9 (an odd number), the median is the ((9+1)/2)th term, that is the 5th term, which is 5. The reason gives a perfect explanation of the assertion.
The incorrect option is B because the reason refers to the exact mathematical principle involved.
The incorrect option is C because R is a mathematically correct theorem.
The incorrect option is D because A is factually true.
Hint: Always make sure the data is sorted before calculating the median, even though the natural numbers are already in order.

Q8. (History Nationalism in India MCQ) Which of the following events took place first during the Indian National Movement?
A. The Rowlatt Act being passed [Correct]
B. The Chauri Chaura affair
C. The agreement reached by Gandhi and Irwin
D. The start of the Civil Disobedience Movement

Option (Correct) — Reason: A. Because the Rowlatt Act was passed. The Rowlatt Act was enacted in 1919. The Chauri Chaura incident took place in 1922. The Civil Disobedience Movement was launched in 1930. The Gandhi-Irwin Pact was signed in 1931.
Option (Incorrect) — Reason: B. Since this event occurred three years after the Rowlatt Act.
Option (Incorrect) — Reason: C. As the movement concluded much later in 1931.
Option (Incorrect) — Reason: D. Because it began in 1930 with the Salt March.
Hint: Order the events by the decades in which they took place.

Q9. (Economics Money & Credit Competency MCQ) A rural farmer depends on informal sources of credit. Which of the following is a typical feature of informal credit?
A. The interest rates which are fixed and low are kept under observation by the RBI.
B. Need for strict collateral paperwork
C. The high level of interest rates possibly leading to a debt trap [Correct]
D. Regular audits carried out by cooperative societies

Option (Correct) -> Reason: C. The high interest rates result in a possible debt trap. Informal sources of finance, such as moneylenders and traders, operate outside the supervision of the RBI, charge exorbitant interest rates, and often cause borrowers to fall into debt traps.
Option (Incorrect) -> Reason: A. This refers to loans from the formal sector (banks).
Option (Incorrect) -> Reason: B. Informal lenders generally do not require strict documentation.
Option (Incorrect) -> Reason: D. Audits are only applicable to formal cooperatives and banks.
Hint: Consider why rural farmers have difficulties when dealing with local moneylenders.

Q10. (English Reported Speech Error-Correction) Select the correct indirect speech version of: The teacher said to the students, "Have you completed your project?"
A. The teacher questioned the students as to whether they had finished their project.
B. The teacher asked the students whether they had finished their project. [Correct]
C. The teacher informed the students about whether they had finished their project.
D. The teacher asked the students that if they had finished their project.

Option (Correct) -> Reason: B. (Assuming B was intended as the correct equivalent of A from previous text, let's fix the options to match standard format).
Let's rewrite the options clearly:
A. The teacher asked the students if they had completed their project. [Correct]
B. The teacher asked the students if they have completed your project.
C. The teacher told the students whether they had completed their project.
D. The teacher asked the students that if they had completed their project.

Option (Correct) -> Reason: A. The teacher asked the students if they had completed their project. The reporting verb "said to" has been changed to "asked". The interrogative sentence uses "if" or "whether". The present perfect tense ("Have you completed") has been changed to the past perfect ("had completed") and the pronouns have been used correctly.
Option (Incorrect) -> Reason: B. It does not backshift the tense and incorrectly keeps "your".
Option (Incorrect) -> Reason: C. "Told" is not appropriate in the case of an interrogative sentence.
Option (Incorrect) -> Reason: D. "That" cannot be used together with "if".
Hint: In indirect speech, questions do not use the conjunction 'that'.

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