COMMON ASSESSMENT EXAM 2025 (MOCK TEST) SCIENCE

1. A: Astigmatism usually is caused by an irregularly shaped cornea.
B: Rainbow is the natural phenomenon in which dispersion takes place.

2. Which of the following statements is true?

3. A concave mirror of focal length 20 cm forms an image having twice the size of object.
For the virtual position of object, the position of object will be at

4. A rectangular coil of copper wire is rotated in a magnetic field. The direction of induced current changes once in each:

5. The force experienced by a current-carrying conductor placed in a magnetic field is the largest when the angle between the conductor and the magnetic field is:

6. Safar cannot see through the fog while driving, because

7. A TV set consumes an electric power of 230 watts and runs on a 230 volts mains supply. The correct fuse for this TV set is:

8. Two resistances 10 Ω and 3 Ω are connected in parallel across a battery. If there is a current of 0.2 A in 10 resistors, the voltage supplied by the battery is:

9. The mains power supply of a house is through a 2A fuse. How many 50W bulbs can be used in this house at the normal voltage?

10. If the current I through a resistor is increased by 100% (assume that temperature remains unchanged), the increase in power dissipated will be:

11. The front face of a circular loop of a wire is the North Pole, the direction of current in this face of the loop will be:

12. A________________ consists of a piece of wire made of metal or an alloy (37% lead, 63% tin).

13. The focal length of the eye lens increases when eye muscles

14. A Person got his eye tested. The optician‟s prescription for the
spectacles was: Left eye: −3 D
Right eye: −3.50 D
The person is having a defect of vision called:

15. The refractive index of flint glass is 1.65 and that for alcohol is 1.36 with respect to air. What is the refractive index of the flint glass with respect to alcohol?

16. Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam?

17. Find out the exothermic processes from the following reactions:

(i) Reaction of water with quicklime

(ii) Dilution of an acid

(iii) Evaporation of water

(iv) Sublimation of camphor (crystals)

18. A clean aluminium foil was placed in an aqueous solution of zinc sulphate. When the aluminium foil was taken out of the zinc sulphate solution after 15 minutes, its surface was found to be coated with a silvery grey deposit. From the above observation it can be concluded that:

19. Which of the metals are refined by electrolytic refining?

(i) Au                       (ii) Cu                          (iii) Na                    (iv) K

20. An element X reacts with hydrogen, when heated, to form a covalent hydride H₂X. If H₂X has the smell of rotten eggs, the element X is likely to be

21. Which of the following hydrocarbons undergo addition reaction?

22. A white colour powder’ A’ used in glass and paper industry and removes permanent hardness of water. The compound ‘ A’ is : .

23. Mixing of acid or base with water results in ……… in the concentration of ions per unit volume :

24. Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?
(A) Displacement reaction
(B) Precipitation reaction
(C) Combination reaction
(D) Double displacement reaction

25. In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the given can be used in place of lead nitrate?

26. A substance X, an oxide of a group 2 element, is used intensively in the cement industry. This element is present in bones also. On treatment with water, it forms a solution which turns red litmus blue. Identify X.

27. A student took four metals P, Q, R and S and carried out different experiments to study the properties of
metals. Some of the observations were:
 All metals could not be cut with a knife except metal R
 Metal P combined with oxygen to form an oxide M2O3 which reacted with both acids and bases.
 Reaction with water-
P-Did not react either with cold or hot water but reacted with steam
Q-Reacted with hot water and the metal started floating
R-Reacted violently with cold water
S-Did not react with water at all.
Based on the above observations, answer the following

The increasing order of the reactivity of the four metals is:

28. The atomic numbers of four elements A, B, C and D are 6, 8, 10 and 12 respectively. The two elements which can react to form ionic compounds are

29. Which one of the following salts does not contain water of crystallisation?

30. Which of the following statements is not true:
(i) Alkalies are water soluble bases but all bases are not alkalies.
(ii) Base turns red litmus blue and phenolphthalein solution pink.
(iii) The aqueous solution of bases conduct electricity.
(iv) Bases react with metal oxides to form salt and hydrogen gas.

31. Posture and balance of the body is controlled by

32. The longest fibre on the cell body of a neuron is called

33. How does a mutation in a gene affect protein production?

34. Response of plant roots towards water is called:

35. In artificial kidney, which substance passes from the blood to the dialysis fluid?

36. The main function of abscisic acid in plants is

37. A student sets up an experiment to study the role of enzymes in the digestion of food.

In which test tube, the digestion of protein will occur?

38. Which is not true about haemoglobin?

39. Which of the following endocrine glands does not exist in pairs?

40. Rihaan can use any source of energy for cooking, but he wants to avoid the production of smoke from the source. Which of these sources should he use for cooking?

41. The surprise products formed in the experiment conducted by Miller and Urey were:

42. Which of the following is a pair of analogous organs?

43. How will information travel within a neuron?

44. Choose the function of pancreatic juice from following :

45. The enzyme responsible for the digestion of proteins in the small intestine is: