The CREST Science Olympiad (CSO) is an international competitive exam held online for students in Classes KG-10. For students of Classes KG-2, there will be only one level. There will be 2 levels for students of Classes 3-10. The exam is an objective-type test that the students need to complete in 60 minutes. For students of Classes KG and 1, the exam will be parent/teacher assisted. The time of the exam will be 45 minutes for KG students.
CREST Science Olympiad Class 10th Sample Questions
1. A tank is filled with water to a height of 10 cm. The apparent depth of the stone lying at the bottom of the tank is measured to be 7.5 cm: i. What is the refractive index of water? ii. If water is replaced by a liquid of refractive index 1.6 up to same height, what will be the new apparent depth of the stone?
a) i: 1.43, ii: 6.25 cm b) i: 1.33, ii: 8.25 cm c) i: 1.33, ii: 6.25 cm d) i: 1.43, ii: 9.25 cm
2. Which of the following sequences is in the correct order to know the steps involved to test the presence of starch in a leaf? P – Boil the leaf in alcohol in a water bath Q – Add iodine solution R – Wash the leaf in water S – Boil the leaf in water
a) S, Q, R and P b) P, S, Q and R c) Q, R, P and S d) S, P, R and Q
3. 5 ml of an aqueous solution of barium chloride was taken in a test tube A and an equal amount of sodium sulphate solution was taken in another test tube B. In another beaker, solutions from test tube A and B were added together, and the colour of the precipitate formed was noted.
Which of the following observation is correct? a) Reaction: Double displacement reaction, Precipitate: BaSO4 (white) b) Reaction: Double displacement reaction, Precipitate: Sodium chloride (white) c) Reaction: Displacement reaction, Precipitate: Sodium chloride (yellow) d) Reaction: Displacement reaction, Precipitate: BaSO4 (white)
4. Consider the following experiment: A small amount of sodium bicarbonate is taken in a test tube and a sufficient amount of acetic acid is added to it. In the reaction, a gas is evolved. The evolved gas is then passed through the lime water.
Which of the following is the correct observation of the above experiment? a) The evolved gas is hydrogen and it does not change the colour of lime water. b) The evolved gas is carbon dioxide and it does not change the colour of lime water. c) The evolved gas is hydrogen and it turns the lime water milky. d) The evolved gas is carbon dioxide and it turns the lime water milky
5. Correct the given statements by replacing the underlined words and select the correct option: (i) The leaves of the mimosa plant fold up quickly, when touched with a finger. This is h an example of chemotropism. (ii) Thigmotropism is a nastic movement of a plant part (like petals of flower) in n response to light. (iii) Cytokinins are the plant hormones which causes the bending of the root of the m plant away from a source of light. (iv) Most of the plant hormones promotes the plant growth. Ascorbic acid is a plant b hormone which inhibits the plant growth.
a) i-Thigmonasty, ii-Photonasty, iii-Auxins, iv-Abscisic acid b) i-Chemotropism, ii-Photonasty, iii-Gibberellin, iv-Ethene c) i-Hydrotropism, ii-Chemotropism, iii- Abscisic acid, iv-Ethene d) i- Thigmonasty, ii-Chemotropism, iii- Auxins, iv-Ethene
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