Group A: Chemistry
1. Which of the following elements does not contain a neutron?
Correct Answer: A. H
Explanation: Hydrogen-1 (protium, 1H) has 1 proton and 0 neutrons, making it the only element with no neutrons among common isotopes.
Explanation: Hydrogen-1 (protium, 1H) has 1 proton and 0 neutrons, making it the only element with no neutrons among common isotopes.
2. The oxidation number of Nitrogen is -1 in:
Correct Answer: B. NH2OH
Explanation: In NH2OH (hydroxylamine), nitrogen’s oxidation state is -1, calculated as: 2(+1 for H) + x + (-2 for O) + 1(+1 for H) = 0, so x = -1.
Explanation: In NH2OH (hydroxylamine), nitrogen’s oxidation state is -1, calculated as: 2(+1 for H) + x + (-2 for O) + 1(+1 for H) = 0, so x = -1.
3. The number of unpaired electrons in oxygen is:
Correct Answer: A. 2
Explanation: Oxygen (atomic number 8) has electron configuration 1s22s22p4. The 2p orbitals have 4 electrons, with 2 unpaired (Hund’s rule), giving 2 unpaired electrons.
Explanation: Oxygen (atomic number 8) has electron configuration 1s22s22p4. The 2p orbitals have 4 electrons, with 2 unpaired (Hund’s rule), giving 2 unpaired electrons.
4. The unit of radioactivity is:
Correct Answer: C. Curie
Explanation: The Curie (Ci) is a unit of radioactivity, measuring the rate of radioactive decay (3.7 × 1010 disintegrations per second).
Explanation: The Curie (Ci) is a unit of radioactivity, measuring the rate of radioactive decay (3.7 × 1010 disintegrations per second).
5. Which of the following compounds gives a positive AgNO3 test?
Correct Answer: D. NaCl
Explanation: The AgNO3 test detects chloride ions (Cl-) that form a white AgCl precipitate. NaCl, an ionic compound, dissociates to give Cl-, unlike covalent compounds like CCl4 or CH3Cl.
Explanation: The AgNO3 test detects chloride ions (Cl-) that form a white AgCl precipitate. NaCl, an ionic compound, dissociates to give Cl-, unlike covalent compounds like CCl4 or CH3Cl.
6. "At the same temperature and pressure, equal volumes of all gases have the same number of molecules." This statement belongs to:
Correct Answer: B. Avogadro’s law
Explanation: Avogadro’s law states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.
Explanation: Avogadro’s law states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.
7. A gas diffuses 4 times as fast as O2. The molecular weight of the gas is:
Correct Answer: D. 2
Explanation: By Graham’s law, rate ∝ 1/√M. If the gas diffuses 4 times faster than O2 (M = 32), then Mgas = 32/(42) = 32/16 = 2.
Explanation: By Graham’s law, rate ∝ 1/√M. If the gas diffuses 4 times faster than O2 (M = 32), then Mgas = 32/(42) = 32/16 = 2.
8. In a solution containing 1 mole alcohol and 4 mole water, the mole fraction of alcohol is:
Correct Answer: D. 1/5
Explanation: Mole fraction = moles of alcohol / total moles = 1 / (1 + 4) = 1/5.
Explanation: Mole fraction = moles of alcohol / total moles = 1 / (1 + 4) = 1/5.
9. The oxidation number of Mn in MnO2 is:
Correct Answer: B. +4
Explanation: In MnO2, each O is -2, so 2(-2) = -4. For neutral MnO2, Mn’s oxidation number is +4.
Explanation: In MnO2, each O is -2, so 2(-2) = -4. For neutral MnO2, Mn’s oxidation number is +4.
10. Vapour pressure at equilibrium of a liquid in a closed vessel depends only on:
Correct Answer: B. Temperature
Explanation: Vapour pressure of a liquid at equilibrium depends solely on temperature, as it affects molecular energy.
Explanation: Vapour pressure of a liquid at equilibrium depends solely on temperature, as it affects molecular energy.
11. Which one is Eka silicon?
Correct Answer: D. Ge
Explanation: Mendeleev predicted Eka-silicon as the element below silicon in the periodic table, later identified as germanium (Ge).
Explanation: Mendeleev predicted Eka-silicon as the element below silicon in the periodic table, later identified as germanium (Ge).
12. The compound used as a refrigerant is:
Correct Answer: D. CCl2F2
Explanation: CCl2F2 (Freon-12) is a chlorofluorocarbon used as a refrigerant due to its stability and low boiling point.
Explanation: CCl2F2 (Freon-12) is a chlorofluorocarbon used as a refrigerant due to its stability and low boiling point.
13. Ethylene reacts with alkaline KMnO4 (Bayer's reagent) to form:
Correct Answer: D. Glycol
Explanation: Ethylene (C2H4) reacts with alkaline KMnO4 to form ethylene glycol (HO-CH2-CH2-OH) via hydroxylation.
Explanation: Ethylene (C2H4) reacts with alkaline KMnO4 to form ethylene glycol (HO-CH2-CH2-OH) via hydroxylation.
14. The crystalline form of carbon is:
Correct Answer: D. All of the above
Explanation: Diamond, graphene, and fullerene are all crystalline allotropes of carbon with distinct structures.
Explanation: Diamond, graphene, and fullerene are all crystalline allotropes of carbon with distinct structures.
15. Froth floatation process is done for:
Correct Answer: B. Sulphide ore
Explanation: Froth floatation is used to concentrate sulphide ores (e.g., ZnS) by separating them from impurities using froth.
Explanation: Froth floatation is used to concentrate sulphide ores (e.g., ZnS) by separating them from impurities using froth.
16. 4 g NaOH in 1 L solution is:
Correct Answer: B. 0.1N
Explanation: Normality (N) = (grams of solute / equivalent weight) / volume (L). For NaOH, equivalent weight = 40 g. So, N = (4 / 40) / 1 = 0.1N.
Explanation: Normality (N) = (grams of solute / equivalent weight) / volume (L). For NaOH, equivalent weight = 40 g. So, N = (4 / 40) / 1 = 0.1N.
17. The pH of a solution containing 3.65 g of HCl per litre is:
Correct Answer: C. 1.0
Explanation: Molarity of HCl = (3.65 / 36.5) / 1 = 0.1 M. Since HCl is a strong acid, [H+] = 0.1 M. pH = -log(0.1) = 1.0.
Explanation: Molarity of HCl = (3.65 / 36.5) / 1 = 0.1 M. Since HCl is a strong acid, [H+] = 0.1 M. pH = -log(0.1) = 1.0.
18. The rate constant of a reaction depends upon:
Correct Answer: A. Temperature
Explanation: The rate constant (k) is temperature-dependent, as described by the Arrhenius equation (k = Ae-Ea/RT).
Explanation: The rate constant (k) is temperature-dependent, as described by the Arrhenius equation (k = Ae-Ea/RT).
19. Which of the following metals is readily corroded in moist air?
Correct Answer: D. Fe
Explanation: Iron (Fe) corrodes easily in moist air, forming rust (Fe2O3·xH2O), unlike noble metals like Cu, Ag, or Au.
Explanation: Iron (Fe) corrodes easily in moist air, forming rust (Fe2O3·xH2O), unlike noble metals like Cu, Ag, or Au.
20. When a solid is converted into a liquid, entropy will:
Correct Answer: D. Increase
Explanation: Entropy increases during melting as molecules gain more freedom of movement in the liquid state.
Explanation: Entropy increases during melting as molecules gain more freedom of movement in the liquid state.
21. Lassaigne’s test is not used to detect which one of the following elements in organic compounds?
Correct Answer: D. C
Explanation: Lassaigne’s test detects N, S, and halogens (like Br) in organic compounds but not carbon, which is assumed present.
Explanation: Lassaigne’s test detects N, S, and halogens (like Br) in organic compounds but not carbon, which is assumed present.
22. CH4 is a/an:
Correct Answer: D. Alkane
Explanation: CH4 (methane) is the simplest alkane, a hydrocarbon with single C-C and C-H bonds.
Explanation: CH4 (methane) is the simplest alkane, a hydrocarbon with single C-C and C-H bonds.
23. Ethyne on polymerization gives:
Correct Answer: B. Benzene
Explanation: Ethyne (C2H2) trimerizes under specific conditions (e.g., with a catalyst) to form benzene (C6H6).
Explanation: Ethyne (C2H2) trimerizes under specific conditions (e.g., with a catalyst) to form benzene (C6H6).
24. Toluene on oxidation with alkaline KMnO4 gives:
Correct Answer: A. Benzoic acid
Explanation: Toluene (C6H5CH3) is oxidized by alkaline KMnO4 to benzoic acid (C6H5COOH), converting the methyl group to a carboxyl group.
Explanation: Toluene (C6H5CH3) is oxidized by alkaline KMnO4 to benzoic acid (C6H5COOH), converting the methyl group to a carboxyl group.
25. Which of the following is a Friedel-Crafts catalyst?
Correct Answer: A. AlCl3
Explanation: AlCl3 (aluminum chloride) is a Lewis acid catalyst used in Friedel-Crafts alkylation and acylation reactions.
Explanation: AlCl3 (aluminum chloride) is a Lewis acid catalyst used in Friedel-Crafts alkylation and acylation reactions.
Group B: Biology
26. Study of fossils comes under:
Correct Answer: C. Paleontology
Explanation: Paleontology is the study of fossils to understand ancient life forms and their evolution.
Explanation: Paleontology is the study of fossils to understand ancient life forms and their evolution.
27. Amoeba locomotes by:
Correct Answer: A. Pseudopodia
Explanation: Amoeba moves by extending its pseudopodia, temporary projections of its body.
Explanation: Amoeba moves by extending its pseudopodia, temporary projections of its body.
28. How many pairs of legs do insects have?
Correct Answer: A. Three
Explanation: Insects have three pairs of legs (six legs total), a defining characteristic of the class Insecta.
Explanation: Insects have three pairs of legs (six legs total), a defining characteristic of the class Insecta.
29. Croaking of frog is:
Correct Answer: B. Sex call for female
Explanation: Male frogs croak to attract females during the mating season.
Explanation: Male frogs croak to attract females during the mating season.
30. Which national park in Nepal is designated as a ‘world heritage site’?
Correct Answer: B. Chitwan N P
Explanation: Chitwan National Park is a UNESCO World Heritage Site due to its biodiversity and conservation efforts.
Explanation: Chitwan National Park is a UNESCO World Heritage Site due to its biodiversity and conservation efforts.
31. Where do you find squamous epithelial tissue?
Correct Answer: D. In the cheek wall
Explanation: Squamous epithelial tissue, flat and scale-like, lines surfaces like the cheek wall for protection.
Explanation: Squamous epithelial tissue, flat and scale-like, lines surfaces like the cheek wall for protection.
32. Yolk plug is seen in:
Correct Answer: B. Gastrula
Explanation: The yolk plug is a structure seen during gastrulation, where yolk-rich cells are visible at the blastopore.
Explanation: The yolk plug is a structure seen during gastrulation, where yolk-rich cells are visible at the blastopore.
33. Movement of food in the intestine is by:
Correct Answer: C. Peristalsis
Explanation: Peristalsis is the rhythmic contraction of intestinal muscles to move food through the digestive tract.
Explanation: Peristalsis is the rhythmic contraction of intestinal muscles to move food through the digestive tract.
34. The amount of air always present in lungs is:
Correct Answer: D. Residual volume
Explanation: Residual volume is the air that remains in the lungs after maximum exhalation, preventing collapse.
Explanation: Residual volume is the air that remains in the lungs after maximum exhalation, preventing collapse.
35. The difference of blood pressure between systolic and diastolic phase is:
Correct Answer: A. 40 mm Hg
Explanation: The difference between systolic (120 mm Hg) and diastolic (80 mm Hg) pressure is typically 40 mm Hg (pulse pressure).
Explanation: The difference between systolic (120 mm Hg) and diastolic (80 mm Hg) pressure is typically 40 mm Hg (pulse pressure).
36. Central nervous system consists of:
Correct Answer: C. Brain and spinal cord both
Explanation: The central nervous system (CNS) includes the brain and spinal cord, which coordinate body functions.
Explanation: The central nervous system (CNS) includes the brain and spinal cord, which coordinate body functions.
37. Typhoid is the disease in which there is infection of:
Correct Answer: C. Stomach
Explanation: Typhoid, caused by Salmonella typhi, primarily infects the intestines and stomach, leading to fever and digestive issues.
Explanation: Typhoid, caused by Salmonella typhi, primarily infects the intestines and stomach, leading to fever and digestive issues.
38. Plant cell only must have:
Correct Answer: D. Cell wall
Explanation: Plant cells have a rigid cell wall made of cellulose, absent in animal cells, providing structural support.
Explanation: Plant cells have a rigid cell wall made of cellulose, absent in animal cells, providing structural support.
39. Crossing over occurs in:
Correct Answer: C. Pachytene
Explanation: Crossing over, the exchange of genetic material between homologous chromosomes, occurs during the pachytene stage of meiosis I.
Explanation: Crossing over, the exchange of genetic material between homologous chromosomes, occurs during the pachytene stage of meiosis I.
40. Eukaryotic unicellular organism belongs to:
Correct Answer: B. Protista
Explanation: Eukaryotic unicellular organisms, like amoebas and paramecia, belong to the kingdom Protista.
Explanation: Eukaryotic unicellular organisms, like amoebas and paramecia, belong to the kingdom Protista.
41. Venter is a part of:
Correct Answer: D. Archegonium
Explanation: The venter is the swollen basal part of the archegonium, the female reproductive organ in plants like mosses, containing the egg.
Explanation: The venter is the swollen basal part of the archegonium, the female reproductive organ in plants like mosses, containing the egg.
42. Vascular cryptogam is:
Correct Answer: D. Pteridophytes
Explanation: Pteridophytes (e.g., ferns) are vascular cryptogams, having vascular tissues but reproducing via spores without flowers.
Explanation: Pteridophytes (e.g., ferns) are vascular cryptogams, having vascular tissues but reproducing via spores without flowers.
43. Synecology is the study of:
Correct Answer: B. Community
Explanation: Synecology studies interactions among communities of organisms and their environment.
Explanation: Synecology studies interactions among communities of organisms and their environment.
44. Palisade parenchyma is found in:
Correct Answer: C. Leaf
Explanation: Palisade parenchyma, specialized for photosynthesis, is found in the mesophyll layer of leaves.
Explanation: Palisade parenchyma, specialized for photosynthesis, is found in the mesophyll layer of leaves.
45. Hypodermis in dicot stem is:
Correct Answer: B. Collenchyma
Explanation: The hypodermis in dicot stems is collenchyma, providing flexible support due to thickened cell walls.
Explanation: The hypodermis in dicot stems is collenchyma, providing flexible support due to thickened cell walls.
46. The water is transported up to the leaves through:
Correct Answer: A. Xylem
Explanation: Xylem transports water and minerals from roots to leaves via tracheids and vessels.
Explanation: Xylem transports water and minerals from roots to leaves via tracheids and vessels.
47. Light reaction of photosynthesis takes place in:
Correct Answer: C. Grana
Explanation: The light reaction occurs in the grana (thylakoid membranes) of chloroplasts, producing ATP and NADPH.
Explanation: The light reaction occurs in the grana (thylakoid membranes) of chloroplasts, producing ATP and NADPH.
48. Codon is associated with:
Correct Answer: B. mRNA
Explanation: A codon is a sequence of three nucleotides on mRNA that codes for a specific amino acid during translation.
Explanation: A codon is a sequence of three nucleotides on mRNA that codes for a specific amino acid during translation.
49. Tendency of genes to get inherited together is called:
Correct Answer: C. Linkage
Explanation: Linkage refers to genes on the same chromosome being inherited together due to their physical proximity.
Explanation: Linkage refers to genes on the same chromosome being inherited together due to their physical proximity.
50. Function of tapetum is:
Correct Answer: B. Nutritive
Explanation: The tapetum in anthers nourishes developing pollen grains by supplying nutrients.
Explanation: The tapetum in anthers nourishes developing pollen grains by supplying nutrients.