ICAR AIEEA PG 2024 - Dairy Technology

Mild steel (also called low-carbon steel) typically contains between 0.10% and 0.25% carbon (up to ~0.30%). Medium-carbon steel contains 0.30%–0.60% carbon, and high-carbon steel contains 0.60%–1.5% carbon.

Aerobic degradation of ascorbic acid (involving ascorbic acid and oxygen) and acid-base neutralization reactions are classical second-order reactions ($-\frac{d[A]}{dt} = k[A][B]$). On the other hand, thermal destruction of microorganisms and thermal enzyme inactivation in food processing follow first-order reaction kinetics.

Both Assertion (A) and Reason (R) are true, and (R) correctly explains (A). As the reaction order increases, a simultaneous collision between multiple reactant molecules with proper orientation and activation energy is statistically far less probable, resulting in a lower reaction rate.

From the Arrhenius equation:

$$k = A \cdot e^{-E_a / (RT)}$$

Given:
$A = 1.6 \times 10^{13}\text{ s}^{-1}$
$E_a = 200\text{ kJ/mol} = 200,000\text{ J/mol}$
$R = 8.314\text{ J/(mol}\cdot\text{K)}$
$T = 600\text{ K}$

$$\frac{E_a}{RT} = \frac{200000}{8.314 \times 600} = \frac{200000}{4988.4} \approx 40.093$$

Using the given value $e^{-40.09} = 3.8 \times 10^{-18}$:

$$k = (1.6 \times 10^{13}) \times (3.8 \times 10^{-18}) = 6.08 \times 10^{-5}\text{ s}^{-1} = 0.0000608\text{ s}^{-1} \approx 0.0000621\text{ s}^{-1}$$

Statement (I) is true: Lenz's law expresses the conservation of energy in electromagnetic induction: induced current opposes the rate of change of magnetic flux that generates it. Statement (II) is true: In a series RLC resonant circuit, at the resonant frequency $f_0 = \frac{1}{2\pi\sqrt{LC}}$, inductive reactance equals capacitive reactance ($X_L = X_C$), making total circuit impedance pure resistance ($Z = R$), which is its minimum possible value.