Prepare for the National Defence Academy and Naval Academy Examination (NDA & NA) with authentic, official previous years' solved question papers across Mathematics (Algebra, Matrices, Trigonometry, Analytical Geometry, Differential & Integral Calculus, Vector Algebra, Statistics & Probability) and General Ability Test (Part A: English Vocabulary & Grammar; Part B: Physics, Chemistry, General Science, History, Freedom Movement, Geography & Current Events).
Marking pattern: Official UPSC NDA Negative Scheme (Mathematics: 120 Qs / 300 Marks [+2.50, -0.83]; GAT: 150 Qs / 600 Marks [+4.00, -1.33]).
Consider the following statements regarding oxidation numbers:
I. The oxidation number of oxygen in peroxides and superoxides is assigned as -1 and -1/2 respectively.
II. In all its compounds, fluorine has an oxidation number of -1.
III. In a reduction half-reaction, the oxidation number of the reductant decreases.
Which of the statements given above are correct?
Consider the following statements regarding the properties of hydrogen and water:
I. Tritium, the isotope of hydrogen, is radioactive and emits low energy alpha particles.
II. In the gas phase, the structure of water is linear.
III. The basic principle of a hydrogen economy is the transportation and storage of energy in the form of liquid or gaseous molecular hydrogen.
Which of the statements given above is/are not correct?
Consider the following statements regarding nitrogen:
I. Nitrogen contains a triple bond.
II. Nitrogen is a triatomic gas.
III. Forces acting between nitrogen molecules are weak van der Waals forces.
Which of the statements given above are correct?
In a dry test tube, 2 mL of HCl (0.1 N) is taken. To this, 4 mL of NaOH (0.1 N) is added. The solution is stirred well, followed by the addition of 2 drops of phenolphthalein. What will be the colour of the solution?
Consider the following statements:
I. Zinc metal, when treated with both HCl (aq.) and NaOH (aq.) separately, produces molecular hydrogen.
II. An aqueous copper sulphate solution cannot be kept in a zinc vessel.
III. Lemon, tamarind and tomato are natural sources of citric acid, oxalic acid and tartaric acid, respectively.
Which of the statements given above are correct?
Consider the following statements:
I. A solution of iodine in ethanol known as 'tincture of iodine' is a heterogeneous mixture.
II. A suspension is a heterogeneous mixture and its particles scatter a beam of light passing through it, making its path visible.
III. A colloidal solution, although it appears homogeneous, is a heterogeneous mixture.
Which of the statements given above are correct?
Consider the following statements:
I. A 30% solution of hydrogen peroxide is marketed as '10 volume' $\text{H}_{2}\text{O}_{2}$.
II. In the compound copper sulphate pentahydrate, all the five water molecules are hydrogen bonded.
Which of the statements given above is/are correct?
Consider the following statements:
I. The leaves of nettle, a herbaceous plant, cause painful stings when touched accidentally because of the secretion of formic acid.
II. When gypsum is heated at $100^{\circ}\text{C}$, it forms calcium carbonate hemihydrate, called Plaster of Paris.
III. When moistened with water, anhydrous copper sulphate forms a green-coloured copper sulphate dihydrate.
Which of the statements given above is/are correct?
Consider the following pairs:
| No. | Chemical Reaction | Type of Chemical Reaction |
|---|---|---|
| I. | $$\text{Fe}(s) + \text{CuSO}_4(aq.) \rightarrow \text{FeSO}_4(aq.) + \text{Cu}(s)$$ | Displacement reaction |
| II. | $$\text{Na}_2\text{SO}_4(aq.) + \text{BaCl}_2(aq.) \rightarrow \text{BaSO}_4(s) + 2\text{NaCl}(aq.)$$ | Double displacement reaction |
| III. | $$\text{Fe}_2\text{O}_3(s) + 3\text{CO}(g) \rightarrow 2\text{Fe}(s) + 3\text{CO}_2(g)$$ | Redox reaction |
| IV. | $$2\text{KClO}_3(s) \rightarrow 2\text{KCl}(s) + 3\text{O}_2(g)$$ | Thermal decomposition reaction |
How many of the pairs given above are correctly matched?
What are the approximate percentages by mass of nitrogen and hydrogen respectively in urea?
Coconut oil upon hydrolysis with potassium hydroxide gives:
Consider the following statements regarding hydrogen bonds:
I. Hydrogen bonds can only form when hydrogen is bonded to oxygen, nitrogen or fluorine.
II. Hydrogen bonds are intramolecular only.
III. The strength of a hydrogen bond decreases with a decrease in the electronegativity of the two bonded atoms.
Which of the statements given above is/are not correct?
Ionic compounds have high melting and boiling points. This is due to:
Which of the following statements is/are correct in respect of Portland cement?
I. Adding more water (higher water-cement ratio) accelerates the initial setting time of cement.
II. The addition of a small percentage of gypsum gives the desired retardation.
III. Gypsum is added during manufacturing to accelerate the setting time of cement.
Select the answer using the code given below:
Consider the following pairs:
| No. | Example of Colloid | Type of Colloid |
|---|---|---|
| I. | Cloud | Aerosol |
| II. | Mud | Sol |
| III. | Milk | Emulsion |
| IV. | Rubber | Foam |
How many of the pairs given above are correctly matched ?
Consider the following statements in relation to respiration in animals:
Which of the statements given above is/are correct?
In humans, the exit of partially digested food from the stomach into the small intestine is regulated by which one of the following structures/processes?
Which of the following cells form components of complex permanent tissue in plants?
Select the answer using the code given below:
Which one of the following is not a part of the hindbrain of human beings?
Which of the following organisms show external fertilization?
Select the answer using the code given below:
Which one of the following plant groups is characterized by having a haploid plant body?
A flower typically is composed of:
Which one of the following organelles is found in both prokaryotic and eukaryotic cells?
Which one of the following is not a connective tissue in the human body?
Which one of the following is not a characteristic of an insect-pollinated plant?