Right Answer: The overall heat transfer coefficient (U) represents the total heat transfer through a system, accounting for all resistances (conductive, convective, and sometimes radiative) in series. In contrast, individual heat transfer coefficients (h) refer to the specific rates of heat transfer due to convection or conduction at different surfaces or layers within the system.
Ques:- Three solid objects of the same material and of equal mass ?a sphere, a cylinder (length = diameter) and a cube ? are at5000C initially. These are dropped in a quenching bath containing a large volume of cooling oil each attaining thebath temperature eventually. The time required for 90%change of temperature is smallest for a) cube b) cylinderc) sphere d) equal for all the three
Right Answer: Extreme points in a Vapor-Liquid Equilibrium (VLE) curve represent the pure components of a mixture, where one phase is entirely vapor and the other is entirely liquid.
Right Answer: A concrete test is a procedure used to assess the properties and quality of concrete, typically involving tests like slump test, compressive strength test, and air content test to ensure it meets specified standards and performance criteria.
Right Answer: The overall heat transfer coefficient (U) represents the total heat transfer through a system, accounting for all resistances (conduction, convection, and sometimes radiation) in series. In contrast, individual heat transfer coefficients (h) refer to the specific rates of heat transfer for each mode (e.g., convection on the fluid side, conduction through a solid, and convection on the other fluid side) separately.
Right Answer: The different characteristics that can affect the flow of bulk solids include:
1. **Particle Size and Shape**: Larger or irregularly shaped particles can lead to poor flow due to interlocking.
2. **Moisture Content**: Higher moisture can cause clumping, while too little can lead to dust.
3. **Density**: Variations in bulk density can affect how solids pack and flow.
4. **Cohesion**: Strong cohesive forces can hinder flow, causing materials to stick together.
5. **Angle of Repose**: The steepest angle at which a pile of bulk material can remain stable affects flowability.
6. **Temperature**: Changes in temperature can alter material properties, impacting flow.
7. **Surface Roughness**: Smoother surfaces can reduce friction and improve flow, while rough surfaces can increase resistance.
8. **Additives**: The presence of flow aids or anti-caking agents can enhance or inhibit flow.
Right Answer: Water has a higher boiling point (100°C) compared to toluene (110.6°C), and it also forms strong hydrogen bonds, which require more energy to break. This results in a longer distillation time for water.
Ques:- The Grashof Number is(a)thermal diffusivity/mass diffusivity (b)inertial force/surface tension force (c)sensible heat / latent heat(d)buoyancy force / viscous force?
Moody's upgraded India's credit rating to Baa2 from Baa3 due to improvements in the country's economic growth prospects, fiscal management, and structural reforms that enhance its creditworthiness.
Right Answer: The 3rd Law of Thermodynamics states that as the temperature of a system approaches absolute zero, the entropy of a perfect crystal approaches zero.
Right Answer: Yes, Bernoulli's theorem can be applied to gases, as they can be treated as fluids under certain conditions, particularly when the flow is incompressible or at low speeds.
Right Answer: Coagulation is the process of destabilizing particles in a liquid to form small aggregates, while flocculation is the subsequent process where these aggregates clump together to form larger particles or flocs.
Right Answer: Vapor pressure of a liquid is the pressure exerted by its vapor when the liquid and vapor are in equilibrium at a given temperature. It is important for pump operations because if the vapor pressure is too high, it can lead to cavitation, causing damage to the pump and reducing its efficiency.
