The first law of thermodynamics:
- The first law of thermodynamics states that the change in internal energy of a system is equal to the sum of the heat exchanged with the surroundings and the amount of work done by the surrounding on the system.
⇒ Q = W + ΔU
Where U = internal energy of the system, Q = amount of heat, and W = work done
- The first law of thermodynamics gives the concept of internal energy.
The Second Law of Thermodynamics states that the state of entropy of the entire universe, as an isolated system, will always increase over time. The second law also states that the changes in the entropy in the universe can never be negative.
The Kelvin-Plack statement of the second law of thermodynamics states that " it is impossible for the cyclic device to absorb heat energy from a single reservoir and to deliver equivalent amount heat "
- Working principle of hydraulic lift is based on PASCLES LAW
- Pascal’s Law is the principle of transmission of fluid-pressure
Is the point, where three phases exists together = TRIPLE POINT
q) In a vapour compression system, the highest temperature during the cycle occurs after _______. compression
Q) Grate is the place in the boiler where FUEL IS BURNT
Q) NWhich of the following cycles is most suitable for steam power plants? Rankine cycle:
Q) Otto cycle:
The air-standard-Otto cycle is the idealized cycle for the spark-ignition internal combustion engines.
Dual cycle
The Dual Cycle also called a mixed cycle or limited pressure cycle is a compromise between Otto and Diesel cycles.
An air-standard diesel cycle consists of - one constant pressure, one constant volume and two adiabatic processes
Q) Venturimeter:
- Venturimeter is a device used for finding out the discharge of a fluid flowing through a pipeline.
- It consists of a converging tube, a small throat section, and a divergent tube.
- Depending upon the carbon content, plain carbon steel can be divided into the following types:
- Dead carbon steel — up to 0.05% to 0.15% carbon
- Low carbon or mild steel — 0.15% to 0.45% carbon
- Medium carbon steel — 0.45% to 0.8% carbon
- High carbon steel — 0.8% to 2% carbon
Iron Loss or Core Loss:
(i) Hysteresis loss:
(ii) Eddy current loss:
The frequency of rotor current or rotor induced EMF in an induction motor is,
fr = sf
where,
s is slip
f is supply frequency
Ns=120fP
s=Ns−NrNs
- Buchholz Relay is used for the protection of transformer from the internal faults.
Type of Cable Voltage level (kV)
- Low tension (L.T.) Cable 0 – 1 kV
- High tension (H.T.) Cable 1 – 11 kV
- Super tension (S.T.) Cable 11 – 33 kV
- Extra high-tension (E.H.T.) Cable 33 – 66 kV
- Extra super-tension(E.S.T.) Cable 66 kV and above From the given options, the voltage level used in the high-tension cables to transmit power is up to 11,000 V.
The zener diode is used as a Shunt voltage regulator for regulating voltage across small loads
Q) Which of the following is used for speed control of DC motor? Ward Leonard Method
Q) A tank circuit is a combination of pure inductance and pure capacitance connected in parallel. It does not contain any resistance values.
Q) Which of the following instruments is used to measure insulation resistance? = MEGGER
