1. What is automatic Valve?

A valve assisted by a spring,'which is opened by a difference of pressure acting in one direction and closed by a difference in pressure acting in the opposite direction.

2. What is case-Harden?

To harden the outer surface of metal to a given case or shell depth, while leaving the inner portion soft to absorb shocks and allow bending.

3. What is analog Sensor?

A sensor which sends a range of voltages in DC to the ECM to describe, for example, coolant temperature, engine oil pressure, or atmospheric pressure.

4. What is air Signal Attenuator?

A device that reduces both exhaust smoke and noise by slowing engine acceleration slightly until adequate turbocharger boost pressure is present.

5. What is critical Speeds?

Speeds at which the frequency of the power strokes synchronize with the crankshaft's natural frequency. If the engine is operated at one of its critical speeds for any length of time, a broken crankshaft may result.

6. What is brake Thermal Efficiency?

Ratio of power output in the form of brake horsepower to equivalent power input in the form of heat from fuel. Typical brake thermal effidency ranges from thirty to forty-two percent.

7. Tell me what are different types of vehicles based on diesel engines?

Automobiles, trucks, buses, marines, and construction areas are popular types that are based on diesel engines.

8. Do you know what is cam?

A rotating component of irregular shape. It is used to change the direction of the motion of another part moving against it, e.g., rotary into reciprocating or variable motion.

9. What is dead Center?

Either of the two positions when the crank and connecting rod are in a straight line at the end of the stroke. The total piston travel is the distance between the two dead center positions.

10. What is relay?

Normally used in control circuits, relay is a switch driven by electricity and rules over contactor by virtue of low amperage contacts.

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