20 Latest Updates in Mechanical Engineering

Latest Updates in Mechanical Engineering Interviews

• 1 HP=how much rpm | Latest Updates in Mechanical Engineering

We need Torque to find out.

Apply this formula:

T = HP x 5252
           rpm

T = torque (in lb-ft).
HP = horsepower
5252 = constant
rpm = revolutions per minute.

• Which mechanism is used in the automobile gearing system?

Differential mechanism

• Why are different types of sounds produced in different bikes even though they say they run on SI engines?

Engine specifications are different in different manufacturers, such as bore diameter(cc), and ignition timing. Also, the exhaust passage takes more responsible for the sound.

• Why does entropy decrease with the increase in temperature?

ds=dQ/T

Entropy is inversely proportional to temperature. As the temperature increases, entropy decreases.

• What type of metal is used in a propeller | Latest Updates in Mechanical Engineering

Aluminum, stainless steel, magnesium, bronze, NIBRAL (nickel, brass, aluminum)

• Why is an involute curve used in gears? The Latest Updates in Mechanical Engineering

1. It’s smooth to drive the gears.
2. in gears contact is the only point, this type is curve takes more load than the normal one

• How Trains take turns, though there is no differential.

The purpose of the differential is to enable vehicles to take turns, by allowing both wheels to rotate at different speeds. This is required when wheels, like in a car, are connected by the same axle. Interestingly, wheels in trains are not connected with the axle, they are independent and, hence, can take turns without any differential. This is the same as how the bullock cart takes turns, without any differential.

• In the condensation of the steam power plant, steam is sent on the shell side and cooling water on the tube side because

  1. To increase the overall heat transfer coefficient of waterside velocity can be increased if water is on the tube side.
  2. A condenser can act as a storage unit for condensed steam.
  3. The rate of condensation of steam is invariably smaller than the mass flow rate of cooling water.
  4. It is easier to maintain a vacuum on the shell side than on the tube side.

Answer:

1. To increase the overall heat transfer coefficient of the waterside velocity can be increased if water is on the tube side.

Reason:

The specific volume of steam is larger, so more volume is required in the condenser.

• Why is the freezer in the fridge placed on the top level? | Latest Updates in Mechanical Engineering

Because the density of cold air is higher than that of warm air, hence, it is placed at the top. Cold air comes downward and cools the bottom part.

• What is more dangerous, longitudinal stress or hoop stress, and why? | Latest Updates in Mechanical Engineering

Hoop stress is more dangerous than longitudinal stress, because the dangerous area coming under the hoop stress is circumferential, while in longitudinal, the axial area will come under the dangerous area will be less than the circumferential area. So hoop stress is more dangerous than longitudinal stress.

• In a spray washing system, if the water temperature is higher than the dry bulb temperature of entering air, then the air is

  1. Heated and dehumidified
  2. Heated and humidified.
  3. Cooled and humidified
  4. Cooled and dehumidified

Answer:

Heated and humidified.

Why is a fine-grained structure harder than a coarse-grained structure? The Latest Updates in Mechanical Engineering

Answer:

The smaller the grain size, the more frequent the pile-up of dislocations. With the decrease in grain size, the mean distance of dislocation can travel decreases, and soon there starts to be a pile-up of dislocations at grain boundaries. This leads to an increase in the yield strength of the material.

• A diesel engine is usually more efficient than a spark ignition engine because | Latest Updates in Mechanical Engineering

Answer:

A diesel engine is usually more fuel-efficient than a gasoline engine. This means less gas is needed to go farther or faster. Diesel engines are also quieter, cleaner, and less polluting. If you want to save money on your next car purchase, consider buying a diesel.

Diesel Engines are more fuel-efficient than Spark Ignition Engines. They are also quiet, clean, and less polluting compared to Spark Ignition Engines. The main reason why they are more fuel-efficient is that they use compression ignition (also called CNG). In contrast, Spark ignitions burn gasoline directly without using a preheating phase.