Pharmaceutical Engineering Quiz

Explanation
Hand mills are used for grinding small quantities of mineral origin drug compounds. This is because mineral origin drug compounds are typically harder and require more force to grind compared to compounds of animal or vegetable origin. Hand mills provide a manual grinding method that allows for greater control and precision when grinding small quantities of these harder compounds. Additionally, hand mills are often used for grinding minerals in various industries, making them a suitable tool for grinding mineral origin drug compounds.

Explanation
The correct answer is "All of the above." This means that fluid energy mill is known by all three names: Micronizers, Jet mill, and Pulverizers.

Explanation
The end runner mill operates by crushing and grinding materials. This means that it uses force to break down the particles into smaller sizes, resulting in a reduction of the material's size. Grinding refers to the process of reducing the size of particles by applying pressure or friction, while crushing involves breaking down materials into smaller pieces by applying force. Therefore, the correct answer is "Crushing and grinding."

Explanation
A cutter mill is a type of machine used for size reduction of materials. It is fitted with both stationary and rotating knives. The stationary knives remain fixed in position, while the rotating knives spin and cut the materials. Having both types of knives allows for efficient and effective cutting of the materials.

Explanation
A hammer mill is an impact mechanism mill because it operates by repeatedly striking the material with high-speed rotating hammers. This impact force breaks down the particles and reduces their size. The hammers in a hammer mill are attached to a rotor that spins at high speed, creating the impact necessary for grinding or pulverizing materials.

Explanation
The emissivity of a black body is a measure of its ability to emit thermal radiation. A black body is an idealized object that absorbs all incident radiation and emits radiation at all wavelengths. The emissivity of a black body is defined as 1, indicating that it emits radiation at the maximum possible rate for a given temperature. Therefore, the correct answer is 1.

Explanation
Mean free path is associated with steam distillation. In steam distillation, the process involves the separation of volatile compounds from non-volatile substances using steam. The mean free path is a concept in physics that represents the average distance traveled by a molecule between collisions with other molecules. In steam distillation, the mean free path is important as it determines the efficiency of the process in terms of the separation of volatile compounds from the mixture.

Explanation
Fluidized bed dryers use hot air jets to dry materials. In this type of dryer, the material to be dried is suspended in a fluidized bed, which is created by blowing hot air through the bed. The hot air jets circulate and mix the material, ensuring efficient drying. Therefore, the correct answer is fluidized bed dryer.

Explanation
Most evaporators use steam as the source of heat. Steam is a commonly used heat transfer medium in industrial processes due to its high heat capacity and ability to transfer heat efficiently. It is easily generated and can be controlled accurately, making it ideal for evaporators. Coal and oil bath may be used in some specific cases, but steam is the most widely used and preferred source of heat in evaporators.