IECS 2025 Quiz 2

If in the circuit (a) with R₁ = 1000 Ω, C₁ = 100 μF, R₂ = 250 Ω, find the value of passive elements in circuit (b), R₃(Ω), R₄(Ω), and C₂ (μF) assuming total impedance of both the circuits are equivalent.

• 200, 50, 1500

• 50, 100, 1000

• 200, 100,2500

• 200, 50, 2500

A lithium-ion battery uses TiS₂ as cathode material. At 50% DOD, what is the fraction of octahedral sites occupied in the cathode?

• 25

• 50

• 75

• 100

Calculate the steady-state diffusional flux of Cl⁻ ions (mol m⁻² s⁻¹) in to the surface of an electrode if the concentration gradient is 0.5068 mol dm⁻³ cm⁻¹. (b) Calculate the magnitude of the diffusion current density (in A m⁻²) for the oxidation of chloride ions at a given overpotential. Consider D_Cl⁻ = 2.032x10⁻⁵ cm² s⁻¹.

• 9.94

• 8.56

• 4.97

• 11.32

What is the quantity of LiCoO₂ and TiS₂ (cathodes) required in grams to construct 3000 mAh Li-ion battery? (atomic mass of Li, Co, Ti, S, O are 6.94, 58.9, 47.8, 32 and 15.99 u)

• 21.9, 12.52

• 18.62, 14.3

• 12.52, 21.9

• 15.66, 12.52

In Na_0.5Fe[Fe(CN)₆] and NaFe[Fe(CN)₆] the ratio of Fe³⁺/Fe²⁺ are

• 3,2

• 2,3

• 3,1

• 1,1

• 0.522 V, 10

• 2.61 V, 5

• 1.05 V, 1

• 0.261 V, 10

• Li₄Ti₅O₁₂, 3

• Li₇Ti₅O₁₂, 3

• Li₄Ti₅O₁₂, 5

• Li₇Ti₅O₁₂, 5

Calculate the period for one complete cycle of a wave in seconds formed by combining sine waves of frequencies 1 Hz, 1.8 Hz and 2 Hz.

• 2

• 3

• 4

• 5

Refer to the diagram. What is the impedance of the circuit?

• 294-38.3j

• 294+38.3j

• 38.3+294j

• 332.3

0.15 M Potassium Ferro cyanide solution was electrochemically oxidized into Ferri cyanide in a rotating disk electrode (RDE) measurement. Assuming kinematic viscosity of the solution as 1.0074 x 10^-6 m²/s, and slope obtained in Koutecky-Levich plot as 466 s^1/2 A^-1, calculate the diffusion coefficient of potassium ferro cyanide in cm²/s.

• 1.56*10^-7

• 9.98*10^-6

• 1.18*10^-7

• 2.26*10^-7