10th Science Quarterly Exam 2024 Question Paper & Solutions | Virudhunagar District
Virudhunagar District - Common Quarterly Examination - September 2024
Standard 10 - SCIENCE
Time: 3.00 Hrs.
Marks: 75
I. Choose the correct answer (12 x 1 = 12)
1) In which of the following sport the turning of effect of force used
2) Power of a lens is -4D then its focal length is
3) The value of universal gas constant
4) Which of the following is correct?
5) The volume occupied by 1 mol of a diatomic gas as STP is
6) Chemical formula of rust is
7) Solubility of NaCl in 100 ml water is 36g. If 20g of salt is dissolved in 100 ml of water. How much more salt is required for saturation
8) Which is formed during anaerobic respiration?
9) The body of leech has
10) Vomitting centre is located in
11) ________ is found abundantly in liquid endosperm of coconut.
12) ________ the units form the backbone of the DNA.
II. Short answer questions: [Any seven only] (7 x 2 = 14)
[Question No. 15 is compulsory]
13) While catching a cricket ball the fielder lowers his hands backwards. Why?
14) What is refractive index?
15) How many electrons are passing per second in a circuit in which there is a current of 5A?
16) Give two examples of heterodiatomic molecules.
17) Classify the following substances into deliquescent, hygroscopic: Conc. sulphuric acid, copper sulphate, penta hydrate, silicagel, calcium chloride and gypsum salt.
18) What is respiratory quotient?
19) How are arteries and veins structurally different from one another?
20) What is bolting? How can it be induced artificially?
21) Name of the secondary sex organs in male.
22) What are allosomes?
III. Long answer questions: [Write any seven only] (7 x 4 = 28)
[Question No. 26 is compulsory]
23) State Newton's laws of motion.
24) Derive the ideal gas equation.
25) a) What are the advantages of LED TV over the normal TV?
b) Write the advantages of LED bulb.
26) A is a reddish brown metal, which combines with O₂ at <1370K giving B a black coloured compound. At a temperature >1370K. A gives C which is red in colour. Find A, B and C with reaction.
27) In what way hygroscopic substances differ from deliquescent substances.
28) Describe and name three stages of cellular respiration that aerobic organisms used to obtain energy from glucose.
29) How does locomotion take place in leech?
30) What is transpiration? Give the importance of transpiration.
31) With a labelled diagram explain the structure of a Neuron.
32) a) Differentiate Monohybrid Cross and Dihybrid Cross.
b) What are Okazaki fragments?
IV. Answer in detail: (3 x 7 = 21)
33) a) Describe the rocket propulsion.
b) List any three properties of light.
(OR)
i) What is meant by electrical current?
ii) Name and define its unit.
iii) Which Instrument is used to measure the electric current? How should it be connected in a circuit?
34) Derive the relationship between Relative molecular mass and vapour density.
(OR)
i) What happens when MgSO₄·7H₂O is heated? Write the appropriate equation.
ii) Define - Solubility.
iii) Differentiate Saturated solution - Unsaturated solution
35) a) Write the physiological effects of gibberellins.
b) Where are the Estrogens produced? What is the role of estrogens in the human body?
(OR)
i) With a neat labelled diagram describe the parts of a typical angiospermic ovule.
ii) Write significance of DNA.
Solutions
Part I: Choose the correct answer
- c) Cycling - Cycling involves applying force to the pedals to create a turning effect (torque) on the crank, and a turning effect on the handlebars to steer.
- c) -0.25m - Formula: Focal length (f) = 1 / Power (P). Given P = -4D. So, f = 1 / (-4) = -0.25 m.
- d) 8.31 J mol⁻¹ K⁻¹ - The standard value of the universal gas constant (R) is approximately 8.314 J mol⁻¹ K⁻¹.
- b) Rate of change of charge is current. - This is the definition of electric current (I = Q/t).
- c) 22.4 litre - According to Avogadro's law, 1 mole of any gas at Standard Temperature and Pressure (STP) occupies a volume of 22.4 litres.
- c) Fe₂O₃·xH₂O - Rust is hydrated iron(III) oxide.
- c) 16g - Solubility is 36g per 100ml. Amount already dissolved = 20g. Amount required for saturation = 36g - 20g = 16g.
- b) Ethyl alcohol - In anaerobic respiration (like in yeast), glucose is broken down into ethyl alcohol and carbon dioxide.
- b) 33 segments - The body of a leech is metamerically segmented into 33 segments.
- a) Medulla oblongata - The vomiting centre is located in the medulla oblongata of the hindbrain.
- b) Cytokinin - Cytokinin is a plant hormone that promotes cell division and is found abundantly in the liquid endosperm of coconut (coconut water).
- d) Sugar phosphate - The backbone of a DNA strand is made of alternating sugar (deoxyribose) and phosphate groups.
Part II: Short answer questions
13) While catching a cricket ball the fielder lowers his hands backwards. Why?
Answer: According to Newton's second law of motion, the force (F) is equal to the rate of change of momentum (Δp/Δt). By lowering his hands backwards, the fielder increases the time (Δt) over which the ball's momentum is brought to zero. Since force is inversely proportional to time, increasing the time of impact reduces the force exerted by the ball on the fielder's hands, thus preventing injury.14) What is refractive index?
Answer: The refractive index of a medium is defined as the ratio of the speed of light in a vacuum to the speed of light in that medium.Refractive Index (μ) = Speed of light in vacuum (c) / Speed of light in medium (v)
It is a dimensionless quantity that measures how much a light ray bends when it enters a medium from a vacuum.
15) How many electrons are passing per second in a circuit in which there is a current of 5A? [Compulsory]
Answer: Given: Current (I) = 5 A, Time (t) = 1 s. We know, Charge (Q) = Current (I) × Time (t) Q = 5 A × 1 s = 5 C We also know that the charge of one electron (e) = 1.6 × 10⁻¹⁹ C. Number of electrons (n) = Total Charge (Q) / Charge of one electron (e) n = 5 / (1.6 × 10⁻¹⁹) n = 3.125 × 10¹⁹ electrons. Therefore, 3.125 × 10¹⁹ electrons pass per second.16) Give two examples of heterodiatomic molecules.
Answer: Heterodiatomic molecules are molecules composed of two atoms of different elements.- Hydrogen Chloride (HCl)
- Carbon Monoxide (CO)
17) Classify the following substances into deliquescent, hygroscopic: Conc. sulphuric acid, copper sulphate pentahydrate, silicagel, calcium chloride and gypsum salt.
Answer:- Deliquescent: Calcium chloride (It absorbs enough moisture from the air to dissolve and form a solution).
- Hygroscopic: Conc. sulphuric acid, Silicagel (They absorb moisture from the air without changing their physical state).
18) What is respiratory quotient?
Answer: The Respiratory Quotient (RQ) is the ratio of the volume of carbon dioxide (CO₂) evolved to the volume of oxygen (O₂) consumed during respiration.RQ = Volume of CO₂ liberated / Volume of O₂ consumed
It varies with the respiratory substrate used.
19) How are arteries and veins structurally different from one another?
Answer:| Feature | Arteries | Veins |
|---|---|---|
| Wall | Thick, muscular, and elastic | Thin, less muscular, and less elastic |
| Lumen | Narrow | Wide |
| Valves | Absent (except at the start of aorta and pulmonary artery) | Present, to prevent the backflow of blood |
20) What is bolting? How can it be induced artificially?
Answer: Bolting is the sudden elongation of the internodes of the stem just prior to flowering in rosette plants like cabbage and beet. This process is naturally induced by certain environmental cues like long days or cold temperatures.Artificially, bolting can be induced by the application of the plant hormone gibberellin.
21) Name of the secondary sex organs in male.
Answer: The secondary (or accessory) sex organs in males include the vas deferens, epididymis, seminal vesicles, prostate gland, and bulbourethral glands.22) What are allosomes?
Answer: Allosomes are the sex chromosomes that are responsible for determining the sex of an individual. In humans, they are the X and Y chromosomes. Females have two X chromosomes (XX), and males have one X and one Y chromosome (XY).