Core Questions for Mechanical Engineering

[Brunon]

Hello, I had gone for an interview at J.B Steel company. At first there was an aptitude test, which was cleared. After that there was a GD round which was also cleared. And at the last there was a HR and Technical round where the HR manager asked some questions to me.3 questions were normal which I had answered but after that the questions were quite different from conventional ones.He asked me about the working and how to repair Hydraulic Jack. I answered about the working but about repair I was not knowing. Pls help me out to answer the question.

[Engg.]

Actually, Hydraulic jacks are typically used for shop works. Hydraulic jack uses a fluid, which is incompressible, that is forced into a cylinder by a pump plunger.As you know about the working, coming straight to the repair part. In general, it is very simple, first polish the scored cylinders and pistons ,then replace worn seals, after that replace excessively worn or damaged parts with new ones. Hope this will help you out

[Masters]

I am doing my mechanical engineering and I am in last year.My final exams are coming near and I am having doubts in few questions. Below are the questions: 1) Tell me the difference why trucks, cars,etc have there silencer under the vehicle while loaders, tractors have there silencer above the vehicle.
2) Tell me about the sensor. Please give the appropriate solution as I am in much need of this.

[Recruiter]

At first,all the best for your final exam.The answer to your question is that the tractors are mainly used for agriculture purpose and in fields. Any spark coming from the silencer will damage the crops, so it is placed upward rather than downwards. Coming to 2nd question: A sensor is a technological device that detects, or senses, a signal or physical condition and chemical compounds. E.g A magnetic device used to sense the opening of a door on a burgular alarm system.

[G-MAT]

After studying everything,I can tell that JCB, tractors are all off road vehicles.There prime function is in field for agriculture, ploughing of tractors. Silencers are placed in vertical direction or in front so as to cut off the interaction with mud stones which can choke it which will not affect the crops. Coming to sensor,in electronic term, sensor is a device that detects the presence or absence of something .For eg a PIR sensor controls security lights. Other types of sensor may be used to measure parameters such as light or heat.