List of top Mechanical Engineering Questions

A system at 500 K receives 7200 kJ/min of heat from a source at 1000 K The ambient temperature is 300 K The system and source temperature remain constant during heat transfer The decrease in available energy due to heat transfer through finite temperature difference is

Lumped Heat capacity analysis can be applied to a system when

Given below are two statements:
Statement (A): The flow in a pipe is turbulent when the Reynolds’ Number is more than 4000.
Statement (R): The flow in a pipe is turbulent at entry and slowly changes to laminar along the length of the pipe.
In light of the above statements, choose the correct answer from the options given below:

Consider the following statements about the flow in a convergent-divergent nozzle operating under design conditions:

1. In the divergent section, pressure is higher than the pressure in the convergent section.
2. The pressure at the throat is equal to critical pressure.
3. The pressure in the convergent section reduces.
4. The flow is subsonic in the convergent section and supersonic in the divergent section.

Choose the correct answer from the options given below.

Given below are two statements one is labelled as Assertion A and the other one labelled as Reason R

The vacuum in a closed container is 50 mm of Hg The absolute pressure in the container is

What are the number of numbers possible divisible by 3 if we choose 4 numbers from the set S = {4,5,7,8,9}