Q1: Define Thermodynamics.
Ans: Thermodynamics is the branch of science that deals with heat, work, energy, and the relationship between them. It studies how energy is transferred and converted in different systems.
Q2: Name the types of units.
Ans: The types of units are:
- ➔ Basic Units
- ➔ Derived Units
Q3: Define Basic Units.
Ans: Basic units are the fundamental units which cannot be expressed in terms of other units. They form the base for all other units.
Q4: Name some Basic Units.
Ans: Some basic units are:
- ➔ Meter (m)
- ➔ Kilogram (kg)
- ➔ Second (s)
- ➔ Ampere (A)
- ➔ Kelvin (K)
Q5: Define Derived Units.
Ans: Derived units are the units which are obtained by combining two or more basic units according to physical laws.
Q6: Name some Derived Units.
Ans: Some derived units are:
- ➔ Newton (N)
- ➔ Joule (J)
- ➔ Watt (W)
- ➔ Pascal (Pa)
Q7: Name the Systems of Units.
Ans: The systems of units are:
- ➔ F.P.S System (Foot Pound Second System)
- ➔ M.K.S System (Meter Kilogram Second System)
- ➔ C.G.S System (Centimeter Gram Second System)
- ➔ S.I Units (System of International Units)
Q8: Define Power.
Ans: Power is the rate of doing work. It tells how fast work is done or energy is transferred.
Power = Work Done / Time
Q9: Write the unit of Power.
Ans: The SI unit of power is Watt (W). One watt is equal to one joule of work done per second.
Q10: Define System.
Ans: A system is a definite portion of matter or space selected for study. Everything outside the system is called surroundings.
Q11: Define Thermodynamic System.
Ans: A thermodynamic system is a quantity of matter or a region in space chosen for thermodynamic study where energy transfer may occur.
Q12: State the classification of System.
Ans: The system is classified as:
- ➔ Closed System
- ➔ Open System
Q13: Define Closed System.
Ans: A closed system is a system in which mass does not cross the boundary, but energy transfer in the form of heat or work can occur.
Q14: Define Open System.
Ans: An open system is a system in which both mass and energy can cross the system boundary.
Q15: What are the Extensive properties of a system?
Ans: Extensive properties are the properties that depend on the quantity or size of the system. Examples include mass, volume, and total energy.
Q16: What are the Intensive properties of a system?
Ans: Intensive properties are the properties that do not depend on the size or quantity of the system. Examples include temperature, pressure, and density.
Q17: Define Heat.
Ans: Heat is a form of energy that is transferred from one body to another due to temperature difference.
Q18: Define Heat Transfer.
Ans: Heat transfer is the movement of heat energy from a higher temperature body to a lower temperature body.
Q19: Name the methods of Heat Transfer.
Ans: The methods of heat transfer are:
- ➔ Conduction
- ➔ Convection
- ➔ Radiation
Q20: Define Conduction.
Ans: Conduction is the method of heat transfer in which heat flows from one part of a body to another or from one body to another through direct contact, without movement of the particles.
Q21: Define Convection.
Ans: Convection is the method of heat transfer in which heat is transferred by the actual movement of fluid particles such as liquids or gases from one place to another.
Q22: Define Radiation.
Ans: Radiation is the method of heat transfer in which heat is transferred in the form of electromagnetic waves without the need of any material medium.
Q23: Define Mass.
Ans: Mass is the amount of matter present in a body. It remains constant irrespective of location.
Q24: Define Weight.
Ans: Weight is the force with which the earth attracts a body. It depends on gravitational acceleration.
Q25: Define Gravitational Acceleration.
Ans: Gravitational acceleration is the acceleration produced on a body due to the force of gravity. Its standard value on earth is 9.81 m/s².
Q26: Define Force.
Ans: Force is a push or pull that can change the state of rest or motion of a body. It is equal to mass multiplied by acceleration.
Q27: Define Work.
Ans: Work is done when a force moves a body through a certain distance in the direction of the force. The formula of Work is as under:
Work = Force x Distance
Q28: Define Pressure.
Ans: Pressure is the force acting per unit area. It is equal to force divided by area.
Q29: Define Normal Pressure.
Ans: Normal pressure is the atmospheric pressure at sea level under normal conditions. It is equal to 1 atmosphere (1 atm) or 760 mm of mercury.
Q30: Define Standard Pressure.
Ans: Standard pressure is the reference pressure used for scientific calculations. It is equal to 1 atmosphere or 101.325 kPa.
Q31: Define Atmospheric Pressure.
Ans: Atmospheric pressure is the pressure exerted by the weight of air present in the atmosphere on the surface of the earth.
Q32: Define Vacuum Pressure.
Ans: Vacuum pressure is the pressure below atmospheric pressure. It shows how much the pressure is less than the surrounding atmospheric pressure.
Q33: Define Absolute Zero Pressure.
Ans: Absolute zero pressure is the pressure measured from absolute vacuum. At this condition, there is no pressure because no molecules are present.
Q34: Define Absolute Pressure.
Ans: Absolute pressure is the total pressure measured from absolute zero pressure. It is equal to atmospheric pressure plus gauge pressure.
Q35: Define Gauge Pressure.
Ans: Gauge pressure is the pressure measured above atmospheric pressure. It does not include atmospheric pressure.
Q36: Define Temperature.
Ans: Temperature is the measure of the degree of hotness or coldness of a body. It indicates the level of heat energy present in a substance.
Q37: Define Thermometer.
Ans: A thermometer is an instrument used to measure the temperature of a body or substance.
Q38: Define Gas Thermometer.
Ans: A gas thermometer is a thermometer that measures temperature by observing the change in pressure or volume of a gas.
Q39: Define Mercury Thermometer.
Ans: A mercury thermometer is a thermometer that uses mercury as the working substance to measure temperature.
Q40: Name the temperature scales.
Ans: The temperature scales are:
- ➔ Celsius Scale
- ➔ Fahrenheit Scale
- ➔ Kelvin Scale
Q41: Define Celsius or Centigrade Scale.
Ans: Celsius or Centigrade scale is the temperature scale in which the freezing point of water is 0°C and the boiling point is 100°C at standard atmospheric pressure.
Q42: Define Kelvin Scale.
Ans: Kelvin scale is the absolute temperature scale in which 0 K represents absolute zero temperature. It is used in scientific calculations.
Q43: Define Fahrenheit Scale.
Ans: Fahrenheit scale is the temperature scale in which the freezing point of water is 32°F and the boiling point is 212°F at standard atmospheric pressure.
Q44: Define Absolute Temperature.
Ans: Absolute temperature is the temperature measured from absolute zero on the Kelvin scale.
Q45: Define Normal Temperature.
Ans: Normal temperature is the ordinary temperature of surroundings, generally taken as 0°C for reference in calculations.
Q46: Define Standard Temperature.
Ans: Standard temperature is the reference temperature used in scientific work, usually taken as 0°C or 273 K.
Q47: Write the units of the followings.
Ans: | Measuring Unit | F.P.S | M.K.S | S.I |
|---|
| Force | Pound (lb) | Kilogram-force (kgf) | Newton (N) |
| Distance | Foot (ft) | Meter (m) | Meter (m) |
| Time | Second (s) | Second (s) | Second (s) |
| Work | Foot-pound (ft·lb) | Kilogram-meter (kg·m) | Joule (J) |
| Velocity | Foot per second (ft/s) | Meter per second (m/s) | Meter per second (m/s) |
| Acceleration | Foot per second² (ft/s²) | Meter per second² (m/s²) | Meter per second² (m/s²) |
| Power | Horsepower (HP) | Kilogram-meter per second (kg·m/s) | Watt (W) |
Q48: Define Energy.
Ans: Energy is the capacity of a system to do work. It can exist in various forms such as heat, mechanical, chemical, or electrical energy.
Q49: Name the types of energy found in the system.
Ans: The types of energy are:
- ➔ Stored Energy
- ➔ Transit Energy
Q50: Define Stored Energy.
Ans: Stored energy is the energy contained within a system at a given instant. It includes potential energy, kinetic energy, and internal energy.
Q51: Define Transit Energy.
Ans: Transit energy is the energy that crosses the boundary of a system in the form of work or heat during a process.
Q52: Define Potential Energy.
Ans: Potential energy is the energy possessed by a body due to its position or configuration relative to a reference point.
Q53: Define Kinetic Energy.
Ans: Kinetic energy is the energy possessed by a body due to its motion. It is proportional to the mass and square of velocity of the body.
Q54: Define Internal Energy.
Ans: Internal energy is the energy stored within a system due to the random motion and interactions of its molecules.
Q55: State the laws of Thermodynamics.
Ans: The laws of thermodynamics include: Zeroth Law, First Law, Second Law, and Third Law. These laws govern the behavior of energy, heat, and work in a system.
Q56: Define Zeroth Law of Thermodynamics.
Ans: Zeroth Law of Thermodynamics states that if two systems are in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
Q57: Define First Law of Thermodynamics.
Ans: The First Law of Thermodynamics states that energy can neither be created nor destroyed; it can only be transformed from one form to another. The change in internal energy equals heat added minus work done by the system.
Q58: State the limitations of First Law of Thermodynamics.
Ans: The First Law does not indicate the direction of energy transfer and cannot predict whether a process will occur spontaneously. It only quantifies energy changes.
Q59: Define Second Law of Thermodynamics.
Ans: The Second Law of Thermodynamics states that heat cannot spontaneously flow from a colder body to a hotter body, and all natural processes increase the entropy of the universe.
Q60: What is Kelvin-Planck Statement?
Ans: Kelvin-Planck Statement states that it is impossible to construct a heat engine that converts all the heat absorbed from a source into work without any other effect.
Q61: What is Clausius Statement?
Ans: Clausius Statement states that it is impossible for a process to transfer heat from a colder body to a hotter body without doing external work.
Q62: State the Law of Conservation of Energy.
Ans: The Law of Conservation of Energy states that the total energy of an isolated system remains constant; energy can change form but the total amount does not change.
Q63: State the Law of Conservation of Matter.
Ans: The Law of Conservation of Matter states that matter can neither be created nor destroyed in a chemical reaction; the total mass remains constant.
Q64: What is the formula of Horse Power in M.K.S?
Ans: Its formula is:
Q65: What is the formula of Horse Power in F.P.S?
Ans: Its formula is:
Q66: What is the formula of Power in S.I?
Ans: Its formula is:
