From the wave equation y=0.5 sin[(2π/3.2)(64t−x)], what is the frequency of the wave?
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Correct answer: (C) 20 Hz
1 marks · 2023 · Set A
Question 52
Identify which expression is not Maxwell’s equation for time-varying fields.
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Correct answer: (A) ∇·J + ∂ρ/∂t = 0
1 marks · 2023 · Set A
Question 53
The voltage induced across a stationary conductor in an external static magnetic field
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Correct answer: (C) Is zero
1 marks · 2023 · Set A
Question 54
A wire in the shape of an equilateral triangle with sides of length 1 m sits in a magnetic field of 2 T pointing to the right. What is the magnitude of the magnetic flux through the triangle?
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Correct answer: (A) 0 Wb
1 marks · 2023 · Set A
Question 55
Which statement(s) is/are true regarding Biot–Savart law? (i) Magnetic field is directly proportional to the length of the element. (ii) Biot–Savart law deals with electric field. (iii) Magnetic field is directly proportional to current through the conductor. Select the correct answer.
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Correct answer: (C) (i) and (iii)
1 marks · 2023 · Set A
Question 56
Find the value of current i in the given circuit (as shown in the printed diagram).
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Correct answer: (C) 1 A
1 marks · 2023 · Set A
Question 57
Which statement is not correct about the quality factor of a parallel resonance circuit?
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Correct answer: (D) More than one of the above
1 marks · 2023 · Set A
Question 58
In a photoelectric experiment, sodium (work function 2.3 eV) and tungsten (work function 4.5 eV) are illuminated by ultraviolet light of the same wavelength. If tungsten’s stopping potential is 1.8 V, what is sodium’s stopping potential?
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Correct answer: (A) 4 V
1 marks · 2023 · Set A
Question 59
The fine structure of atomic spectral lines arises from
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Correct answer: (A) Electron spin–orbit coupling
1 marks · 2023 · Set A
Question 60
An atom with proton number 84 and nucleon number 216 decays by emitting an alpha particle. What is the structure of the new nucleus?
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Correct answer: (A) Proton number 82, nucleon number 212
1 marks · 2023 · Set A
Question 61
Which of the following reactions is not allowed?
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Correct answer: (B) Λ⁺ + n → Σ⁺ + p
1 marks · 2023 · Set A
Question 62
Donor-type impurities are materials of which group of the periodic table?
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Correct answer: (A) Group V
1 marks · 2023 · Set A
Question 63
In an n-type semiconductor, the Fermi level lies
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Correct answer: (B) Below the bottom of the conduction band
1 marks · 2023 · Set A
Question 64
The maximum efficiency of a half-wave rectifier is
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Correct answer: (B) 40.6%
1 marks · 2023 · Set A
Question 65
Consider: (i) amplitude modulation, (ii) frequency modulation, (iii) phase modulation, (iv) pulse modulation. Which are used for telecasting TV programmes?
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Correct answer: (C) (i) and (ii)
1 marks · 2023 · Set A
Question 66
For every 10°C increase in temperature, the reverse saturation current of a p–n junction increases by
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Correct answer: (B) 2 times
1 marks · 2023 · Set A
Question 67
The band-gap energies of silicon and germanium photodiodes are 1.1 eV and 0.67 eV respectively. What are their respective cutoff wavelengths?
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Correct answer: (A) 1127.27 nm, 1850.75 nm
1 marks · 2023 · Set A
Question 68
Which method can produce a high degree of homogeneity in the creation of ZnFe₂O₄ spinel?
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Correct answer: (C) Coprecipitation method
1 marks · 2023 · Set A
Question 69
_____ is a crystalline solid’s basic repetitive structural unit.
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Correct answer: (C) Unit cell
1 marks · 2023 · Set A
Question 70
For all the reactions, what is the nature of chemical dissociation?
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Correct answer: (D) More than one of the above
1 marks · 2023 · Set A
Question 71
The radius of an atomic nucleus is of the order of
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Correct answer: (B) 10⁻¹³ cm
1 marks · 2023 · Set A
Question 72
An atomic orbital is
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Correct answer: (C) The region in which there is a maximum probability of finding an electron
1 marks · 2023 · Set A
Question 73
In the rate equation, when the concentration of the reactants is unity, the rate is equal to the
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Correct answer: (A) Specific rate constant
1 marks · 2023 · Set A
Question 74
In the reaction 2A + B → A₂B, if the concentration of A is doubled and that of B is halved, how will the reaction rate change?
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Correct answer: (A) Increase 2 times
1 marks · 2023 · Set A
Question 75
Substance A decomposes by a first-order reaction, starting with [A]=2.00 M. After 200 minutes, [A]=0.15 M. What is t₁/₂?
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Correct answer: (A) 53.72 minutes
1 marks · 2023 · Set A
Question 76
Which assertion about the main cell is correct?
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Correct answer: (A) A mercury cell is an example of a primary cell.
1 marks · 2023 · Set A
Question 77
Which of the following does a catalyst alter in a chemical reaction?
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Correct answer: (B) Activation energy
1 marks · 2023 · Set A
Question 78
Photochemistry deals with the study of
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Correct answer: (C) Reactions that proceed with absorption of visible or ultraviolet light
1 marks · 2023 · Set A
Question 79
The number of photons passing through a unit area in a unit time is called
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Correct answer: (C) Intensity of light
1 marks · 2023 · Set A
Question 80
The transition without radiation emission of a molecule from a stable excited state to an unstable excited state, leading to dissociation, is called
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Correct answer: (A) Predissociation
1 marks · 2023 · Set A
Question 81
Which products are obtained when Na₂CO₃ is added to a copper sulphate solution?
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Correct answer: (A) Basic copper carbonate, sodium sulphate and CO₂
1 marks · 2023 · Set A
Question 82
Which pair has similar atomic radii?
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Correct answer: (B) Mo and W
1 marks · 2023 · Set A
Question 83
According to IUPAC nomenclature, sodium nitroprusside dihydrate is named
Substance X is used in whitewashing and is obtained by heating limestone in the absence of air. Identify X.
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Correct answer: (C) CaO
1 marks · 2023 · Set A
Question 85
Dilute ferrous sulphate solution is gradually added to acidified permanganate solution. The light purple colour fades and disappears. Which explanation is correct?
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Correct answer: (A) KMnO₄ is an oxidizing agent and oxidizes FeSO₄.
1 marks · 2023 · Set A
Question 86
How many structural isomers are possible if one hydrogen atom in diphenylmethane is replaced by chlorine?
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Correct answer: (B) 4
1 marks · 2023 · Set A
Question 87
Which statement(s) is/are true? Prolonged exposure of silver chloride to sunlight turns it grey due to: (i) formation of silver by decomposition of silver chloride; (ii) sublimation of silver chloride; (iii) decomposition of chlorine gas from silver chloride; (iv) oxidation of silver chloride. Select the correct answer.
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Correct answer: (B) (i) and (iii)
1 marks · 2023 · Set A
Question 88
Which of the following is a branched polymer?
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Correct answer: (A) Low-density polymer
1 marks · 2023 · Set A
Question 89
Which monomers form biodegradable polymers?
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Correct answer: (D) More than one of the above
1 marks · 2023 · Set A
Question 90
The correct order of increasing nucleophilicity is
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Correct answer: (A) Cl⁻ < Br⁻ < I⁻
1 marks · 2023 · Set A
Question 91
Select the correct statement.
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Correct answer: (C) Spectroscopic methods require less time and less sample than classical methods.
1 marks · 2023 · Set A
Question 92
A carbonyl group causes a sharp dip at about _____ cm⁻¹.
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Correct answer: (A) 1700
1 marks · 2023 · Set A
Question 93
What is the best method for separating para- and ortho-nitrophenols from a 1:1 mixture?
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Correct answer: (C) Steam distillation
1 marks · 2023 · Set A
Question 94
Which compound undergoes nucleophilic substitution exclusively by an Sₙ1 mechanism?
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Correct answer: (A) Benzyl chloride
1 marks · 2023 · Set A
Question 95
Most phytophagous nematodes are
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Correct answer: (A) Root parasites
1 marks · 2023 · Set A
Question 96
One purpose of secondary treatment of wastewater and sewage is
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Correct answer: (B) To reduce BOD
1 marks · 2023 · Set A
Question 97
Most bacteria that cause plant diseases are members of which group?