Remote sensing

• Short Day Plants $\rightarrow$ (IV) Rice: Rice (Oryza sativa) initiates floral induction only when the photoperiod is shorter than its critical day length.
• Long Day Plants $\rightarrow$ (I) Wheat: Wheat (Triticum aestivum) requires photoperiods longer than its critical day length to transition from vegetative growth to heading and flowering.
• Day Neutral Plants $\rightarrow$ (II) Tomato: Tomato (Solanum lycopersicum) flowers regardless of day length, controlled primarily by physiological node number and vegetative vigor.
• Intermediate Plants $\rightarrow$ (III) Andropogon: Andropogon scoparius requires an intermediate photoperiod window (neither too long nor too short) to initiate flowering.

Correct option: (4) (A) - (IV), (B) - (), (C) - (I), (D) - (ttl)

• Wien's Displacement Law in Remote Sensing:

$$\lambda_{\max} = \frac{b}{T} = \frac{2898\ \mu\text{m}\cdot\text{K}}{T}$$

• Application to Terrestrial Features:
• For Earth features with average kinetic temperatures around $T \approx 300\text{ K}$ ($27^\circ\text{C}$):

$$\lambda_{\max} = \frac{2898}{300} \approx 9.66\ \mu\text{m} \approx 9.7\ \mu\text{m}$$

• Wien's law (A) directly explains why Earth's thermal emission peaks in the thermal infrared atmospheric window around $9.7\ \mu\text{m}$. (Correct answer: Option 1)

• Assertion (A) is True: Soil thermal conductivity ($k$) increases significantly as soil moisture content increases.
• Reason (R) is True: Water is a substantially better heat conductor than air (thermal conductivity of water is approximately $\approx 0.57\ \text{W}\cdot\text{m}^{-1}\cdot\text{K}^{-1}$, which is $\approx 23$ times greater than that of still air $\approx 0.025\ \text{W}\cdot\text{m}^{-1}\cdot\text{K}^{-1}$); water replaces insulating air pockets at inter-particle contact points, creating thermal bridges.
• Relationship: Because water replaces low-conductivity air in soil pores to establish continuous conducting bridges, Reason (R) directly explains Assertion (A).
• Conclusion: Both (A) and (R) are true and (R) is the correct explanation of (A) (Option 1).

Correct option: (1) Both (A) and (R) are true and (R) is the correct explanation of (A)