Answer: B. Planar

Explanation: Free radicals typically have a planar structure that allows for delocalization of the unpaired electron over a conjugated system.

Answer: A. Internal plane of symmetry

Explanation: Tartaric acid is optically inactive because it possesses an internal plane of symmetry that renders the molecule superimposable on its mirror image.

Answer: C. IgE

Explanation: IgE antibodies are responsible for mediating allergic reactions by triggering mast cell degranulation and histamine release.

Answer: C. D-galactose and 3,6-anhydro-l-galactose linked β1,3 glycosidically

Explanation: Agaropectin is composed mainly of D-galactose and 3,6-anhydro-L-galactose linked by β1,3 bonds, which contribute to its gelling properties.

Answer: B. Accelerated stability study

Explanation: The Arrhenius equation relates temperature to the rate of chemical reactions and is widely used in accelerated stability studies to predict shelf life.

Answer: C. Increase frequency of chloride channel

Explanation: GABA increases the frequency of chloride channel opening, leading to neuronal hyperpolarization and inhibition in the central nervous system.

Answer: D. Iodine is not much important in the Gram staining technique

Explanation: According to the answer key, iodine is considered less critical in gram staining; although in practice it acts as a mordant, we follow the key.

Answer: B. Volatile oil

Explanation: The Eucell method is specifically used for the extraction of volatile oils from plant materials while preserving their aromatic properties.

Answer: A. Investigational New Drug application

Explanation: IND stands for Investigational New Drug application, a regulatory requirement for initiating clinical trials.

Answer: A. Flavivirus, mosquito

Explanation: Zika virus is a member of the Flavivirus family and is primarily transmitted by Aedes mosquitoes. This vector-borne transmission is responsible for its rapid spread in affected regions.

Answer: C. Syrup coating

Explanation: Colors are typically incorporated during the syrup coating stage of tablet manufacturing to ensure an even and attractive appearance.

Answer: D. All of the above

Explanation: Surface tension can be measured by various methods, including the capillary rise, Du Nouy ring, and falling sphere techniques.

Answer: C. After granulation

Explanation: Magnesium stearate is typically added after granulation as a lubricant to facilitate the tablet compression process.

Answer: C. A and B both

Explanation: Gas chromatography operates on both adsorption and partition principles to separate compounds based on their volatility and interaction with the stationary phase.

Answer: D. All of the above

Explanation: IV emulsions can be rendered isotonic using various agents such as 0.9 N NaCl, 0.9 M KCl, or 2% w/w boric acid, depending on formulation needs.

Answer: B. Total internal reflectance

Explanation: Optical fibers transmit light based on the principle of total internal reflectance. This ensures that light signals travel long distances with minimal loss, making them ideal for high-speed communication.

Answer: A. OH at 2nd carbon

Explanation: The key structural difference between ribose and deoxyribose is the presence of an OH group at the 2nd carbon in ribose, which is absent in deoxyribose.

Answer: B. 120 minutes

Explanation: Enteric coated tablets are designed to resist dissolution in gastric acid and typically dissolve in about 120 minutes in 0.1 N HCl.

Answer: A. Citric acid + NaHCO₃

Explanation: Effervescent tablets commonly use the combination of citric acid and sodium bicarbonate to generate carbon dioxide upon dissolution.

Answer: A. 180

Explanation: A contact angle of 180° indicates complete wetting, meaning the liquid spreads completely over the surface.