Official TU IOST BSc CSIT Model Question — Unofficial Answer Key

Q1 A sentence x + 7 = 5 is

(a) false statement  (b) true statement  (c) not a statement  (d) a statement

Answer: (c) not a statement

A statement must be definitely true or definitely false. Since x + 7 = 5 is true only when x = −2 and false otherwise, it is an open sentence — its truth value depends on x — so it is not a statement.

Q2 If P and Q are nonempty sets and P ⊂ Q then

(a) P ⊂ Q̄  (b) Q̄ ⊂ P̄  (c) P ∩ Q = ∅  (d) P ⊃ Q

Answer: (b) Q̄ ⊂ P̄

P ⊂ Q means every element of P is in Q. Taking complements reverses the inclusion: anything not in Q is certainly not in P, so Q̄ ⊂ P̄.

Q3 If |x − 3| = 7 then x =

(a) {10, −4}  (b) [10, −4]  (c) {−8, 4}  (d) (10, −4)

Answer: (a) {10, −4}

Remove the modulus: x − 3 = 7 → x = 10, or x − 3 = −7 → x = −4. Solution set = {10, −4}. A set is written in braces, not brackets.

Q4 √(−1) is

(a) an integer  (b) a prime number  (c) an irrational number  (d) a complex number

Answer: (d) a complex number

√(−1) = i, the imaginary unit = 0 + 1·i. It belongs to the set of complex numbers (imaginary numbers are a subset of complex numbers).

Q5 The range of f(x) = √(9 − x²) is

(a) (−3, 3]  (b) [0, 3]  (c) (0, 3)  (d) {0, 2}

Answer: (b) [0, 3]

Domain: 9 − x² ≥ 0 → x ∈ [−3, 3]. Inside the root, 9 − x² runs from 0 (at x = ±3) to 9 (at x = 0), so the square root runs from 0 to 3. Range = [0, 3].

Q6 The function f(x) = sin x + x is

(a) even function  (b) periodic function  (c) odd function  (d) neither even nor odd

Answer: (c) odd function

f(−x) = sin(−x) + (−x) = −sin x − x = −f(x). Since f(−x) = −f(x), it is an odd function.

Q7 If x, y and z are in A.P. then

(a) x + y = z  (b) y + z = 2x  (c) x − z = 2y  (d) x + z = 2y

Answer: (d) x + z = 2y

In an AP the middle term is the average of its neighbours: y − x = z − y → 2y = x + z. So the sum of the extremes equals twice the middle term.

Q8 The determinant of the matrix A = [−3] is

(a) 3  (b) not possible  (c) −3  (d) 0

Answer: (c) −3

The determinant of a 1×1 matrix is simply the element itself: det[−3] = −3.

Q9 If x − iy = (5 + 2i)² then (x, y) is

(a) (21, 20)  (b) (21, −20)  (c) (−21, 20)  (d) (−21, −20)

Answer: (b) (21, −20)

(5 + 2i)² = 25 + 20i + 4i² = 25 + 20i − 4 = 21 + 20i. Matching with x − iy: x = 21 and −y = 20, so y = −20.

Q10 If in a triangle ABC the angles are in A.P., then angle B =

(a) 30°  (b) 45°  (c) 120°  (d) 60°

Answer: (d) 60°

Angles in AP: A + C = 2B. Also A + B + C = 180°. Substituting: 2B + B = 180° → 3B = 180° → B = 60°.

Q11 The area of triangle ABC is

(a) 2bc sinA  (b) bc sinA  (c) ½ bc sinA  (d) ½ bc

Answer: (c) ½ bc sinA

Area = ½ × (side b) × (side c) × sin(included angle A). The sides b and c meet at angle A, so area = ½ bc sinA.

Q12 Equation of a line perpendicular to 2x + 3y + 5 = 0 is

(a) 3x − 2y + 7 = 0  (b) 2x − 3y + 7 = 0  (c) −3x − 2y − 7 = 0  (d) −2x − 3y + 7 = 0

Answer: (a) 3x − 2y + 7 = 0

Two lines a₁x + b₁y + c₁ = 0 and a₂x + b₂y + c₂ = 0 are perpendicular when a₁a₂ + b₁b₂ = 0. Here (2, 3)·(3, −2) = 6 − 6 = 0 ✓

Q13 The two lines represented by ax² + 4xy + 2y² = 0 are perpendicular for a =

(a) 0  (b) −2  (c) 2  (d) 1

Answer: (b) −2

A homogeneous pair ax² + 2hxy + by² = 0 represents perpendicular lines iff a + b = 0. Here 2h = 4 → h = 2 and b = 2, so a + 2 = 0 → a = −2.

Q14 Equation of the tangent at (3, 4) to the circle x² + y² = 25 is

(a) 3x − 4y = 25  (b) 3x + 4y = −25  (c) 4x + 3y = 25  (d) 3x + 4y = 25

Answer: (d) 3x + 4y = 25

Tangent to x² + y² = r² at (x₁, y₁) is xx₁ + yy₁ = r². So 3x + 4y = 25.

Q15 The unit vector along the vector 3i + 4j is

(a) i + j  (b) ⅛(3i − 4j)  (c) ⅛(3i + 4j)  (d) ⅛(i + j)

Answer: (c) ⅛(3i + 4j)

Magnitude |3i + 4j| = √(9 + 16) = 5. Unit vector = vector / magnitude = (3i + 4j)/5.

Q16 The scalar product of 3i − 4j + k and 3i + 4j is

(a) 6  (b) −7  (c) 0  (d) −7i

Answer: (b) −7

Dot product = (3)(3) + (−4)(4) + (1)(0) = 9 − 16 + 0 = −7. Note the answer is a scalar, so (d) −7i is wrong.

Q17 Probability of getting an even number while rolling a die is

(a) 0  (b) 1/3  (c) 1/4  (d) 1/2

Answer: (d) 1/2

Even outcomes on a die: {2, 4, 6} — 3 of the 6 faces. P = 3/6 = 1/2.

Q18 lim_x→3 (x³ − 27)/(x − 3) =

(a) 3  (b) 9  (c) 27  (d) 0/0

Answer: (c) 27

Factor the numerator: x³ − 27 = (x − 3)(x² + 3x + 9). Cancel (x − 3), then evaluate at x = 3: 9 + 9 + 9 = 27.

Q19 The values of x for which dy/dx = 0, for y = x³ − 3x² are

(a) 0, 0  (b) 0, 2  (c) 0, −2  (d) 0, 3/2

Answer: (b) 0, 2

dy/dx = 3x² − 6x = 3x(x − 2). Setting to zero: x = 0 or x = 2.

Q20 If y = e^{log x²} then dy/dx =

(a) 2x  (b) yx  (c) 2x/y  (d) e^{log x²}

Answer: (a) 2x

Assuming log denotes the natural logarithm (as commonly used in TU entrance questions), e^log(x²) = x². Therefore dy/dx = 2x.

Q21 The point of inflection of y = x³ − x² is

(a) 3  (b) 0  (c) 1/3  (d) 1

Answer: (c) 1/3

Inflection requires y″ = 0. y″ = 6x − 2 = 0 → x = 1/3, so the actual point of inflection is (⅓, −2/27) (y = (1/3)³ − (1/3)² = −2/27). Since the options list only x-values, the correct answer is 1/3.

Q22 ∫₀¹ 3x²e^x³ dx =

(a) e − 1  (b) e  (c) 0  (d) e³

Answer: (a) e − 1

Substitute u = x³, du = 3x²dx. Integral becomes ∫ e^u du = e^x³ evaluated 0 to 1 = e¹ − e&sup0; = e − 1.

Q23 Area bounded by the x-axis, the curve y = x², and the lines x = 0 and x = 4 is

(a) 64  (b) 16  (c) 16/3  (d) 64/3

Answer: (d) 64/3

Area = ∫₀⁴ x² dx = [x³/3]₀⁴ = 64/3 − 0 = 64/3 square units.

Q24 If f(x) = x² + 5, the approximate value of f′(2) with Δx = 0.1 is

(a) 6  (b) 4.1  (c) 4.2  (d) 2

Answer: (b) 4.1

Using the forward-difference approximation f′(2) ≈ [f(2 + Δx) − f(2)]/Δx = [f(2.1) − f(2)]/0.1. f(2.1) = 4.41 + 5 = 9.41 and f(2) = 9, so (9.41 − 9)/0.1 = 4.1. (The exact derivative f′(2) = 4; 4.1 is the forward-difference estimate.)

Q25 If two forces P and Q (P > Q) act at a point in the same direction, the resultant is

(a) P − Q  (b) P + Q  (c) PQ  (d) Q − P

Answer: (b) P + Q

Forces in the same direction add. Resultant = P + Q.

Q26 A quantity x is related by x = ⅓(b² − h²)h where a, b and h are lengths. Then x is

(a) length  (b) velocity  (c) area  (d) volume

Answer: (d) volume

Dimensions: b² − h² → [L²], multiplied by h → [L³], and ⅓ is dimensionless. So x has dimensions of volume.

Q27 A vector is multiplied by −2, then

(a) direction reverses and unit changes  (b) direction reverses and magnitude is doubled  (c) direction unchanged but unit changes  (d) direction unchanged, magnitude doubled

Answer: (b) direction reverses and magnitude is doubled

Multiplying by a negative scalar reverses direction; the factor 2 doubles the magnitude.

Q28 A stone is dropped from a height of 45 m. The distance travelled during its last second is

(a) 5 m  (b) 10 m  (c) 25 m  (d) 50 m

Answer: (c) 25 m

Total fall time t = √(2h/g) = √(2×45/9.8) ≈ 3.03 s. Distance in first 2 s = ½g(2)² = 19.6 m. Last second = 45 − 19.6 ≈ 25 m.

Q29 A projectile breaks into two pieces at maximum height. Then its

(a) momentum increases  (b) momentum decreases  (c) kinetic energy increases  (d) kinetic energy decreases

Answer: (c) kinetic energy increases

Explosion is an internal event, so total linear momentum is conserved. But internal (chemical) energy converts into kinetic energy of the pieces, so the total KE increases.

Q30 A jet plane is based on the conservation of

(a) mass  (b) energy  (c) linear momentum  (d) angular momentum

Answer: (c) linear momentum

The engine throws exhaust gas backward; by conservation of linear momentum the plane moves forward with equal and opposite momentum.

Q31 Which of the following possesses the highest viscosity?

(a) water  (b) blood  (c) glycerine  (d) honey

Answer: (d) honey

Viscosity order among these: honey > glycerine > blood > water. Honey flows slowest — it has the highest viscosity.

Q32 The graph of kinetic energy (KE) of a body versus velocity (v) is

(figure-based — pick the graph that matches the description)

Answer: upward-opening parabola with vertex at the origin

Since KE = ½mv², kinetic energy is proportional to the square of the velocity. Therefore the graph is an upward-opening parabola with its vertex at the origin (KE = 0 when v = 0).

Q33 A mass m is attached to two identical springs (frequency f). If one spring is removed, the new frequency is

(a) f  (b) 2f  (c) f√2  (d) f/√2

Answer: (d) f/√2

With two springs in parallel, effective k₁ = k + k = 2k, and ω = √(2k/m). With one spring, ω₂ = √(k/m) = ω/√2. Hence f₂ = f/√2.

Q34 A metal sheet has a circular hole in it. When heated, the diameter of the hole

(a) increases  (b) decreases  (c) remains unchanged  (d) increases then decreases

Answer: (a) increases

The hole expands exactly as if it were filled with the same metal. On heating, the surrounding metal expands outward, so the hole's diameter increases.

Q35 The mean free path of a gas varies with pressure P as

(a) P  (b) P⁻¹  (c) P⁻²  (d) P²

Answer: (b) P⁻¹

Mean free path λ = kT/(√2 π d² P). At constant temperature, λ ∝ 1/P — inversely proportional to pressure.

Q36 A body initially at 100°C cools to 40°C in 10 minutes. Its temperature at the end of 15 minutes will be

(a) 35°C  (b) 30°C  (c) 25°C  (d) 20°C

Answer: (c) 25°C

Newton's law of cooling (taking surroundings near 0°C): θ = θ₀e^−kt. From 100 → 40 in 10 min: ln(100/40) = 10k → k = (ln 2.5)/10 ≈ 0.0916/min. At t = 15: θ = 100e^−1.374 ≈ 25.3°C ≈ 25°C.

Q37 Light of wavelength 550 nm falls normally on a slit of width 22 × 10⁻⁹ m. The angular position of the second minima from the central maxima is

(a) 14.5°  (b) 42°  (c) 30°  (d) 62°

Answer: (c) 30°

Single-slit minima: a sinθ = nλ. For n = 2: sinθ = 2λ/a = 2(550×10⁻⁸)/(22×10⁻⁹) = 0.5. θ = sin⁻¹(0.5) = 30°.

Q38 The variation of intensity with wavelength at different temperatures (figure) will be

(a) T₁ > T₂ > T₃  (b) T₁ > T₃ > T₂  (c) T₂ > T₃ > T₁  (d) T₃ > T₂ > T₁

Answer: (b) T₁ > T₃ > T₂

Wien's displacement law: λ_max ∝ 1/T. A smaller peak wavelength means a higher temperature, and a larger peak wavelength means a lower temperature. In the figure, T₁ peaks at the smallest wavelength (leftmost), T₃ in the middle, and T₂ at the largest wavelength (rightmost). So λ₁ < λ₃ < λ₂, hence T₁ > T₃ > T₂.

Q39 A completely transparent material will be invisible in vacuum when refractive index (μ) is

(a) unity  (b) more than unity  (c) less than unity  (d) infinity

Answer: (a) unity

A material is invisible when light passes through without reflection or refraction at its surface — when its refractive index equals the surrounding medium (vacuum), i.e. μ = 1.

Q40 For a convex mirror, the variation of u and v is given by (figure)

(figure-based — select the graph showing a linear relationship between 1/v and 1/u)

Answer: (c) Graph — 1/v vs 1/u is a straight line

The mirror formula 1/v + 1/u = 1/f is linear in 1/v and 1/u, so the graph of 1/v against 1/u is a straight line, while a direct plot of v vs u is a hyperbola. Select the option that shows this straight-line graph.

Q41 Sweetness of sound depends upon its

(a) wavelength  (b) periodicity  (c) periodicity and regularity  (d) amplitude

Answer: (d) amplitude

Loudness depends on amplitude — larger amplitude means louder sound. The original model paper appears to use "sweetness" where "loudness" is typically intended. Amplitude does not affect pitch (frequency) or quality (timbre), which depends on the waveform and overtones, so the expected answer here is (d) amplitude.

Q42 A parallel-plate capacitor is charged and the battery is disconnected. If the plates are moved further apart,

(a) charge on the capacitor increases  (b) voltage across the plates increases  (c) capacitance increases  (d) energy stored decreases

Answer: (b) voltage across the plates increases

With the battery removed, charge Q stays constant. C = ε₀A/d → increasing d decreases C. Since V = Q/C, a smaller C means V increases. (Energy U = Q²/2C also increases.)

Q43 The equivalent resistance between the points X and Y is

(a) 10 Ω  (b) 20 Ω  (c) 30 Ω  (d) 40 Ω

Answer: (a) 10 Ω

The diagram shows a balanced Wheatstone bridge (10/10 = 10/10), so the central 20 Ω resistor carries no current. The equivalent resistance is (10 + 10) || (10 + 10) = 10 Ω.

Q44 A magnetic needle kept in a non-uniform magnetic field experiences

(a) torque but not a force  (b) neither a force nor a torque  (c) force and a torque  (d) a force but not a torque

Answer: (c) force and a torque

A non-uniform field exerts a force on the needle's poles (strength differs pole to pole) and a torque tending to align it with the field. In a uniform field only torque acts.

Q45 A 34 V, 50 Hz source is connected in series with a coil of 17 mH and a resistor of 10 Ω. The potential difference across the coil is

(a) 12 V  (b) 16 V  (c) 28 V  (d) 32 V

Answer: (b) 16 V

Inductive reactance X_L = 2πfL = 2π(50)(0.017) ≈ 5.34 Ω. Impedance Z = √(R² + X_L²) = √(100 + 28.5) ≈ 11.34 Ω. Current I = 34/11.34 ≈ 3.0 A. Voltage across the coil = IX_L ≈ 3.0 × 5.34 ≈ 16 V.

Q46 A strong argument for the particle nature of cathode rays is that they

(a) produce fluorescence  (b) travel through vacuum  (c) get deflected by electric and magnetic fields  (d) cast shadow

Answer: (c) get deflected by electric and magnetic fields

Deflection by electric and magnetic fields proves that cathode rays consist of charged particles with mass — a key indicator of their particle nature.

Q47 When objects placed in a room are exposed to X-rays, they appear

(a) invisible  (b) yellow  (c) blue  (d) red

Answer: (a) invisible

X-rays are invisible electromagnetic waves. Ordinary objects do not become visibly coloured under X-ray exposure; among the given options, invisible is the expected answer.

Q48 Which series of the hydrogen atom lies in the infrared region?

(a) Lyman  (b) Balmer  (c) Pfund  (d) H-alpha

Answer: (c) Pfund

Lyman → ultraviolet, Balmer → visible. Paschen, Brackett and Pfund all lie in the infrared. Among the options, Pfund.

Q49 When Boron (¹⁰₅B) is bombarded by a neutron, alpha particles are emitted. The resulting nucleus has mass number

(a) 11  (b) 7  (c) 6  (d) 15

Answer: (b) 7

Reaction: ¹⁰₅B + ₀¹n → &sup4;₂He + ⁳₃Li. Mass number: 10 + 1 = 11 = 4 + A → A = 7 (the product is ₃Li⁷, mass number 7).

Q50 In a P-type semiconductor, the majority and minority charge carriers are respectively

(a) protons and electrons  (b) electrons and protons  (c) electrons and holes  (d) holes and electrons

Answer: (d) holes and electrons

P-type material (doped with a trivalent acceptor) has holes as majority carriers and electrons as minority carriers.

Q51 The weight of sodium carbonate required to prepare 100 mL of its decinormal solution is

(a) 0.53 g  (b) 5.3 g  (c) 0.053 g  (d) 5.6 g

Answer: (a) 0.53 g

Na₂CO₃ molar mass = 106 g/mol; n-factor = 2 (dibasic), so equivalent weight = 106/2 = 53. W = (N × E × V)/1000 = (0.1 × 53 × 100)/1000 = 0.53 g.

Q52 The concept of pH was introduced by

(a) Arrhenius  (b) Lewis  (c) Bronsted  (d) Sorensen

Answer: (d) Sorensen

The pH scale (power of hydrogen) was introduced by Danish chemist S.P.L. Sorensen in 1909.

Q53 The rate of a chemical reaction increases with

(a) increase in particle size  (b) increase in temperature  (c) decrease in temperature  (d) decrease in concentration

Answer: (b) increase in temperature

Raising temperature increases molecular kinetic energy and collision frequency, so the reaction rate increases (roughly doubles per 10°C).

Q54 A spontaneous change is one in which the system has

(a) an increase in internal energy  (b) lowering of entropy  (c) lowering of free energy  (d) no energy change

Answer: (c) lowering of free energy

A process is spontaneous when Gibbs free energy decreases: ΔG < 0 (lowering of free energy).

Q55 Which of the following is an example of a transition metal?

(a) cobalt  (b) potassium  (c) magnesium  (d) silicon

Answer: (a) cobalt

Transition metals have partly filled d-orbitals. Cobalt (Co) is a d-block transition metal; K, Mg are s-block and Si is a metalloid.

Q56 Which compound is called blue vitriol?

(a) Cu₂O  (b) CuSO₄·5H₂O  (c) CuCl₂  (d) Cu₂Cl₂

Answer: (b) CuSO₄·5H₂O

Copper(II) sulphate pentahydrate, CuSO₄·5H₂O, is the blue crystalline compound called blue vitriol.

Q57 Silver is extracted from its sulphide ore by

(a) Contact process  (b) Down's process  (c) Cyanide process  (d) Ostwald's process

Answer: (c) Cyanide process

Silver sulphide ore is treated with dilute NaCN solution (MacArthur–Forrest cyanide process) forming soluble complex [Ag(CN)₂]⁻, from which Ag is recovered with Zn.

Q58 2,4-Dichlorophenoxyacetic acid (2,4-D) is generally used as

(a) a herbicide  (b) an insecticide  (c) a fungicide  (d) none of the above

Answer: (a) a herbicide

2,4-D is a widely used selective weed killer — a herbicide.

Q59 A class of organometallic compounds of magnesium, RMgX, is known as

(a) Tollen's reagent  (b) Nessler's reagent  (c) Schiff's reagent  (d) Grignard reagent

Answer: (d) Grignard reagent

Organomagnesium halides RMgX are Grignard reagents — key reagents for carbon–carbon bond formation.

Q60 Aldehydes can be distinguished from ketones by

(a) Fehling's solution  (b) conc. H₂SO₄  (c) Grignard's reagent  (d) pyragallol

Answer: (a) Fehling's solution

Aldehydes reduce Fehling's solution to a red Cu₂O precipitate; simple ketones do not — a classic distinguishing test.

Q61 Picric acid is obtained by the nitration of

(a) aniline  (b) phenol  (c) benzene  (d) benzoic acid

Answer: (b) phenol

Picric acid is 2,4,6-trinitrophenol, made by nitrating phenol (with conc. HNO₃/H₂SO₄).

Q62 Which compound is used as an anaesthetic?

(a) ethylene  (b) ethyl alcohol  (c) chloroform  (d) acetylene

Answer: (c) chloroform

Chloroform (CHCl₃) was historically used as an inhalation anaesthetic.

Q63 An aromatic carboxylic acid is

(a) formic acid  (b) acetic acid  (c) stearic acid  (d) cinnamic acid

Answer: (d) cinnamic acid

Cinnamic acid (C₆H₅–CH=CH–COOH) contains an aromatic benzene ring. Formic, acetic and stearic acids are aliphatic.

Q64 Which compound is called urea?

(a) NH₂CONH₂  (b) NH₂COONH₄  (c) H₂NNHCONH₂  (d) H₂NCONHC₂H₅

Answer: (a) NH₂CONH₂

Urea is carbamide, NH₂CONH₂ (NH₂–CO–NH₂).

Q65 Ethyne reacts with alkaline KMnO₄ solution to give

(a) glyoxal  (b) oxalic acid  (c) ethanoic acid  (d) acetic acid

Answer: (b) oxalic acid

Alkaline KMnO₄ is a strong oxidising agent; it oxidises ethyne (HC≡CH) all the way to oxalic acid (COOH)₂.

Q66 The IUPAC name of acetaldehyde is

(a) methanal  (b) propanal  (c) ethanal  (d) butanal

Answer: (c) ethanal

Acetaldehyde (CH₃CHO) has a 2-carbon chain, so its IUPAC name is ethanal.

Q67 Which is the most toxic chemical form of mercury?

(a) Hg  (b) Hg₂²⁺  (c) Hg²⁺  (d) CH₃Hg⁺

Answer: (d) CH₃Hg⁺

Methylmercury (CH₃Hg⁺) is the most toxic form — it bioaccumulates in the food chain and damages the nervous system.

Q68 The number of molecules in 32 g of oxygen is

(a) 6.02 × 10²³  (b) 6.02 × 10⁸  (c) 3.2 × 10²³  (d) 3.2 × 10⁹⁶

Answer: (a) 6.02 × 10²³

Molar mass of O₂ = 32 g/mol, so 32 g = 1 mole. Number of molecules = Avogadro's number = 6.02 × 10²³.

Q69 The outermost electronic configuration of chromium is

(a) 3d&sup4;4s²  (b) 3d&sup5;4s¹  (c) 3d&sup5;4s²  (d) 3d&sup6;4s²

Answer: (b) 3d&sup5;4s¹

Chromium (Z = 24) is an exception to the aufbau rule — it takes a half-filled d&sup5; configuration (3d&sup5;4s¹) for extra stability.

Q70 Which of the following has the lowest ionic radius?

(a) O²⁻  (b) F⁻  (c) Al³⁺  (d) Na⁺

Answer: (c) Al³⁺

All these ions are isoelectronic (2,8), but ionic radius decreases as nuclear charge increases. Al³⁺ has the highest charge, so the smallest radius.

Q71 Which hydrogen halide has the lowest dipole moment?

(a) HF  (b) HCl  (c) HBr  (d) HI

Answer: (d) HI

Bond polarity decreases down the group (electronegativity difference shrinks), so dipole moment order is HF > HCl > HBr > HI. HI has the lowest.

Q72 The value of the universal gas constant (R) in SI units is

(a) 8.314 J K⁻¹ mol⁻¹  (b) 5.314 J K⁻¹ mol⁻¹  (c) 3.501 J K⁻¹ mol⁻¹  (d) 8.314 × 10⁷ erg K⁻¹ mol⁻¹

Answer: (a) 8.314 J K⁻¹ mol⁻¹

R = 8.314 J K⁻¹ mol⁻¹ in SI units (0.0821 L atm K⁻¹ mol⁻¹ in other units).

Q73 An example of an acidic oxide is

(a) NO  (b) N₂O₅  (c) N₂O  (d) Al₂O₃

Answer: (b) N₂O₅

Non-metal oxides in higher oxidation states are acidic. N₂O₅ (dinitrogen pentoxide) is the acid anhydride of nitric acid. NO and N₂O are neutral; Al₂O₃ is amphoteric.

Q74 The ionic character in the H–X bond is highest in

(a) HCl  (b) HBr  (c) HF  (d) HI

Answer: (c) HF

Ionic character rises with the electronegativity difference. F is the most electronegative element, so HF has the most ionic H–X bond.

Q75 Which of the following compounds is called magnesia?

(a) MgSO₄·7H₂O  (b) MgCl₂·6H₂O  (c) MgCl₂  (d) Mg(OH)₂

Answer: (d) Mg(OH)₂

Strictly, magnesia is MgO, while Mg(OH)₂ is milk of magnesia. The expected answer is (d) Mg(OH)₂ because "milk of magnesia" is the compound commonly intended in entrance exams. (MgSO₄·7H₂O is Epsom salt.)

Q76 The word "headhunter" gets its prime stress on

(a) 1st syllable  (b) 2nd syllable  (c) 3rd syllable  (d) none

Answer: (a) 1st syllable

Compound nouns usually stress the first element: HEAD-hunter.

Q77 Pick the word closest in meaning to "headland"

(a) highland  (b) flat land  (c) promontory  (d) marshy land

Answer: (c) promontory

A headland is a point of land jutting into the sea — a promontory.

Q78 Pick the word closest in meaning to "remarkable"

(a) good  (b) astonishing  (c) commendable  (d) notable

Answer: (d) notable

"Remarkable" means worthy of special attention — the nearest synonym is notable.

Q79 Pick the word opposite in meaning to "pompous"

(a) showy  (b) wealthy  (c) convincing  (d) humble

Answer: (d) humble

"Pompous" means self-important and grand; the opposite is humble (modest, unassuming).

Q80 Pick the word opposite in meaning to "reciprocal"

(a) obstinate  (b) unilateral  (c) mutual  (d) imaginary

Answer: (b) unilateral

"Reciprocal" means mutual/two-sided; the opposite is unilateral (done by one side only).

Q81 Writing with correct spelling is

(a) orthography  (b) homograph  (c) telegraphy  (d) lithography

Answer: (a) orthography

Orthography is the correct spelling and writing of words.

Q82 Choose the correct word order: "We ... cruelty, ... tyranny and ... a flatterer."

(a) hate, abhor, loathe  (b) abhor, hate, loathe  (c) loathe, hate, abhor  (d) abhor, loathe, hate

Answer: (a) hate, abhor, loathe

The words rise in intensity: hate < abhor < loathe. So "We hate cruelty, abhor tyranny and loathe a flatterer."

Q83 Belief that God is nature is

(a) Henotheism  (b) Polytheism  (c) Pantheism  (d) Deism

Answer: (c) Pantheism

Pantheism holds that God and the universe/nature are identical.

Q84 Choose the correct prepositions: "For a week she lived ... banana and milk as she believed ... the prescription of her doctor."

(a) at, on  (b) on, in  (c) in, on  (d) on, on

Answer: (b) on, in

"Lived on banana and milk" (subsisting on food) and "believed in the prescription" (have faith in).

Q85 Choose the correct prepositions: "I am scared ... loss ... my business but keen ... gambling."

(a) in, of, on  (b) on, in, of  (c) in, on, of  (d) of, in, on

Answer: (d) of, in, on

"Scared of loss", "loss in my business", "keen on gambling". Hence of, in, on.

Q86 Pick the correct phrasal verb: "I was the son of sailors and ... stories of the sea."

(a) reared on  (b) reared off  (c) brought on  (d) put on

Answer: (a) reared on

"Reared on" means raised/brought up with (e.g., on stories of the sea).

Q87 Pick the correct phrasal verb: "When does school ... for the summer vacation?"

(a) break out  (b) break up  (c) break off  (d) break in

Answer: (b) break up

"Break up" means to close/disperse at the end of a term — school breaks up for vacation.

Q88 Give the exact meaning of "Bright and breezy"

(a) in very sad mood  (b) in very active mood  (c) in a cheerful mood to do things quickly  (d) in decisive mood

Answer: (c) in a cheerful mood to do things quickly

"Bright and breezy" describes someone cheerful and quick in doing things.

Q89 Give the exact meaning of "Go by the board"

(a) plans discontinued and abandoned  (b) plans in action  (c) with a new plan  (d) no plan for sometime

Answer: (a) plans discontinued and abandoned

"Go by the board" means to be abandoned or discarded (plans given up).

Q90 Use the correct conditional: "You must go tomorrow ... you are ready or not."

(a) if  (b) even if  (c) unless  (d) whether

Answer: (d) whether

The phrase "ready or not" pairs with whether: "You must go tomorrow whether you are ready or not."

Q91 MS-Word is an example of

(a) an operating system  (b) a processing device  (c) application software  (d) an input device

Answer: (c) application software

MS-Word is a word processor — application software that runs on top of an OS.

Q92 A computer cannot "boot" if it does not have the

(a) compiler  (b) loader  (c) operating system  (d) assembler

Answer: (c) operating system

Booting loads the operating system into memory; without an OS the machine cannot boot.

Q93 By default, documents print in ... mode.

(a) Landscape  (b) Portrait  (c) Page Setup  (d) Print View

Answer: (b) Portrait

The default page orientation is portrait (taller than wide).

Q94 Ctrl, Shift and Alt are called ... keys.

(a) modifier  (b) function  (c) alphanumeric  (d) adjustment

Answer: (a) modifier

Ctrl, Shift and Alt modify the meaning of other keys — they are modifier keys.

Q95 Storage which retains data after power off is called

(a) volatile storage  (b) non-volatile storage  (c) sequential storage  (d) direct storage

Answer: (b) non-volatile storage

Storage that keeps data without power is non-volatile (e.g., HDD, SSD, ROM). RAM is volatile.

Q96 What are the four things needed to connect to the internet?

(a) telephone line, modem, computer, and an ISP  (b) modem, computer, PDA, and ISP  (c) telephone line, modem, computer, and PDA  (d) computer, ISP, modem, and communication software

Answer: (a) telephone line, modem, computer, and an ISP

This reflects older computer fundamentals taught in the syllabus — classically, the four essentials are a computer, modem, telephone line and an ISP connection. (Modern connections often use fiber or mobile data, but the textbook answer stands.)

Q97 Which process refers to starting up a computer and loading the required parts of the OS into RAM?

(a) Booting  (b) Tagging  (c) Swiping  (d) Mapping

Answer: (a) Booting

The startup sequence that loads the OS into RAM is called booting.

Q98 In a word document, the term "gutter" stands for

(a) the blank page inserted between filled pages  (b) space on the left for rough work  (c) space between two paragraphs  (d) space left on one side for stitching and binding

Answer: (d) space left on one side for stitching and binding

A gutter margin is the extra space reserved on the binding edge of a page for stitching/binding.

Q99 Programs stored in ROM are called

(a) Fireware  (b) Formware  (c) Farmware  (d) Firmware

Answer: (d) Firmware

Software permanently stored in ROM is called firmware.

Q100 Select the correct statement(s): A. MS-Excel creates workbooks, each with more worksheets. B. A worksheet in MS-Excel 2000 has 256 columns and 65536 rows. C. Columns are identified by a number and rows by a letter. D. Cells are identified by the column letter and the row number.

(a) A, B, C  (b) B, C, D  (c) C, D, A  (d) A, B, D

Answer: (d) A, B, D

A ✓ B ✓ C ✗ (columns are letters, rows are numbers) D ✓. The correct set is A, B, D.