The question asks about the raw material used to produce Plaster of Paris (PoP) through a process called calcination. Understanding the chemical composition and manufacturing process of Plaster of Paris is key to answering this question.
Correct Option: A) Plaster of Paris is chemically calcium sulfate hemihydrate (\(\text{CaSO}_4 \cdot \frac{1}{2}\text{H}_2\text{O}\)). It is produced by heating gypsum (\(\text{CaSO}_4 \cdot 2\text{H}_2\text{O}\)), which is calcium sulfate dihydrate, to a temperature of about \(120-180^\circ\text{C}\). This process is known as calcination, where gypsum loses a part of its water of crystallization.
The question asks about the source material for plywood. Plywood is an engineered wood product made from thin layers of wood veneer, or "plies", glued together. Understanding the general type of wood used for such manufacturing processes is key.
Correct Option: C) Structural timber. Plywood is manufactured from various types of timber that are suitable for structural applications, meaning they can be processed into veneers and provide the necessary strength and stability when laminated.
The question asks to identify the device that is NOT used to measure the rate of flow. We need to evaluate each option based on its primary function in fluid mechanics.
Correct Option: B) Pitot tube
A Pitot tube is primarily used to measure the local velocity of a fluid at a specific point in the flow. It measures the difference between the stagnation pressure and the static pressure, which can then be used to calculate the fluid velocity using Bernoulli's principle. While flow rate can be derived from velocity measurements (by integrating velocity over the cross-sectional area), the Pitot tube itself does not directly measure the rate of flow; it measures velocity.
The question asks about the most suitable terrain for using the intersection method of detailed plotting in surveying. The intersection method is a plane table surveying technique where points are located by the intersection of rays drawn from at least two instrument stations. We need to consider the advantages and limitations of this method in different types of terrain.
Correct Option: C) Hilly areas are most suitable for the intersection method because direct linear measurements are difficult, but good inter-visibility between points from elevated stations is often available, allowing for accurate plotting by intersecting rays.
The question asks for the best compaction method for coarse-grained soils. Compaction aims to increase the density of soil by reducing air voids. Different types of rollers are effective for different soil types based on their compaction mechanisms.
Correct Option: D) Vibratory rollers are the most effective for compacting coarse-grained soils because the vibratory action reduces inter-particle friction, allowing the granular particles to settle into a denser configuration.
The question asks about the carbon content in mild steel. To answer this, we need to recall the classification of steels based on their carbon percentage.
Correct Option: A) Less than 0.25
The question asks about the maximum current an induction meter can handle. Induction meters, commonly used as energy meters, are designed to measure electrical energy consumption. Their current handling capacity is a crucial specification that determines their application range.
D) 100 A — Standard induction-type energy meters are often rated to handle currents up to 100 A. This capacity allows them to measure energy consumption for a wide range of electrical loads found in homes and small businesses.
The question asks about the unit in which induction type single-phase energy meters measure electric energy. Understanding the fundamental units of electrical power and energy is crucial here.
Correct Option: C) kWh
Induction type single-phase energy meters measure electric energy in kilowatt-hours (kWh). This unit represents the consumption of 1 kilowatt of power for 1 hour.
The question asks about the essential parts of a motor meter. A motor meter, such as an energy meter, measures electrical energy consumption. To function correctly, it requires mechanisms to produce rotation proportional to the quantity being measured, control that rotation, and display the measured value.
Correct Option: D) operating torque system, braking device and Revolution registering device
The question asks to identify an instrument used for measuring the insulation resistance of an electric circuit relative to earth and other parts of the circuit. We need to evaluate each option based on its primary function.
B) Megger is an instrument specifically designed to measure high insulation resistance of electrical circuits, cables, and equipment relative to earth and between different conductors. It applies a high DC voltage and measures the resulting current to determine the resistance in megaohms.