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# Test: Basic Concepts of Thermodynamics - 1

## 20 Questions MCQ Test RRB JE for Mechanical Engineering | Test: Basic Concepts of Thermodynamics - 1

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This mock test of Test: Basic Concepts of Thermodynamics - 1 for Mechanical Engineering helps you for every Mechanical Engineering entrance exam. This contains 20 Multiple Choice Questions for Mechanical Engineering Test: Basic Concepts of Thermodynamics - 1 (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Basic Concepts of Thermodynamics - 1 quiz give you a good mix of easy questions and tough questions. Mechanical Engineering students definitely take this Test: Basic Concepts of Thermodynamics - 1 exercise for a better result in the exam. You can find other Test: Basic Concepts of Thermodynamics - 1 extra questions, long questions & short questions for Mechanical Engineering on EduRev as well by searching above.
QUESTION: 1

### Codes:

Solution:

A heat engine is a system that converts heat into work by taking heat from the reservoir ( hot body) to carry out some work. There is a discharge of some heat to the sink (cold body).

Hot Air Balloon is used to lift the weight using heat.

bimetallic strip is used to convert a temperature change into mechanical displacement. The strip consists of two strips of different metals which expand at different rates as they are heated. ... This effect is used in a range of mechanical and electrical devices.

QUESTION: 2

### Heat and work are

Solution:

Heat and work depend upon the path traversed to move from one thermodynamic state to another. This is why they are known as path functions.

QUESTION: 3

### A balloon containing an ideal gas is initially kept in an evacuated and insulated room. The balloon ruptures and the gas fills up the entire room. Which one of the following statements is TRUE at the end of above process?

Solution:

It is free expansion. Since vacuum does not offer any resistance, there is no work transfer involved in free expansion.

QUESTION: 4

A system comprising a single phase is called a

Solution:
QUESTION: 5

The main cause of the irreversibility is

Solution:

There are basically two reasons of irreversibility of a thermodynamic process.

1. Involvement of dissipative effect during the process.
2. Lack of thermodynamic equilibrium during the process.
QUESTION: 6

Which of the following are intensive properties?

1. Kinetic Energy

2. Specific Enthalpy

3. Pressure

4. Entropy

Select the correct answer using the code given below:

Solution:

Option (b) 2 and 3 is  correct.

Specific enthalpy and pressure

Are both intensive properties.

Explanation:-

{ Intensive properties are those that do not depend on the size of the system. Specific enthalpy is the enthalpy on a per gram basis. Since  this value is normalized to the per gram basis it does not depend on the size of the system being measured. }
So, both are intensive properties.

QUESTION: 7

Consider the following:

1. Kinetic energy

2. Entropy

3. Thermal conductivity

4. Pressure

Which of these are intensive properties?

Solution:

Kinetic energy 1/2mv2 depends on mass, Entropy kJ/k depends on mass so Entropy is extensive property but specific entropy kJ/kg K is an intensive property.

QUESTION: 8

Consider the following properties:

1. Entropy

2. Viscosity

3. Temperature

4. Specific heat at constant volume

Which of the above properties of a system is/are extensive?

Solution:

Extensive property: Whose value depends on the size or extent i.e. mass of the system (upper case letters as the symbols) e.g., Volume, Mass (V, M). If mass is increased, the value of extensive property also increases.

QUESTION: 9

In highly rarefied gases, the concept of this loses validity

Solution:
QUESTION: 10

A control volume is

Solution:

A control volume is a mathematical abstraction employed in the process of creating mathematical models of physical processes. In an inertial frame of reference, it is a volume fixed in space or moving with constant flow velocity through which the continuum (gas, liquid or solid) flows. The surface enclosing the control volume is referred to as the control surface.

At steady state, a control volume can be thought of as an arbitrary volume in which the mass of the continuum remains constant. As a continuum moves through the control volume, the mass entering the control volume is equal to the mass leaving the control volume. At steady state, and in the absence of work and heat transfer, the energy within the control volume remains constant. It is analogous to the classical mechanics concept of the free body diagram.

QUESTION: 11

Isothermal compression of air in a Stirling engine is an example of

Solution:
QUESTION: 12

Assertion (A): In thermodynamic analysis, the concept of reversibility is that, a reversible process is the most efficient process.

Reason (R): The energy transfer as heat and work during the forward process as always identically equal to the energy transfer is heat and work during the reversal or the process.

Solution:

The energy transfer as heat and work during the forward process as always
identically equal to the energy transfer is heat and work during the reversal or the process is the correct reason for maximum efficiency because it is conservative system.

QUESTION: 13

Ice kept in a well insulated thermo flask is an example of which system?

Solution:

Isolated System - in which there is no interaction between system and the
surroundings. It is of fixed mass and energy, and hence there is no mass and energy transfer across the system boundary.

QUESTION: 14

A thermodynamic system is considered to be an isolated one if

Solution:

A thermodynamic system is considered to be an isolated one if there is no energy and mass transfer taking place.

QUESTION: 15

Measurement of temperature is based on which law of thermodynamics?

Solution:

All temperature measurements are based on Zeroth law of thermodynamics.

QUESTION: 16

Zeroth Law of thermodynamics states that

Solution:

The Zeroth law of thermodynamics is the basis for measurement of temperature and setting its scale. In simple word, Zeroth law of thermodynamics says that “When two bodies are separately in thermal equilibrium with the third body, then the two are also in thermal equilibrium with each other."

QUESTION: 17

The constant volume gas thermometer works on the principle that

Solution:

We know that PV=mRT and it holds good at low pressure and high temperature. If volume is constant P is proportional to T (since R is constant and m depends on gas and is also constant). Therefore, at low pressure, the temperature of gas is proportional to its pressure at constant volume.

QUESTION: 18

Assertion (a): If an alcohol and a mercury thermometer read exactly 0°C at the ice point and 100°C at the steam point and the distance between the two points is divided into 100 equal parts in both thermometers, the two thermometers will give exactly the same reading at 50°C.

Reason (R): Temperature scales are arbitrary.

Solution:

Because firstly they are of different material they have different thermal expansion etc and secondly no 2 things whether of same company can tel u the same.
Eg. if u purchase the weighing machine of 2 companies even they can' t tell the same weight .. i.e some amt of deflection will be there

QUESTION: 19

Pressure reaches a value of absolute zero

Solution:

Absolute zero, temperature at which a thermodynamic system has the lowest energy. It appeared that an “ideal gas” at constant pressure would reach zero volume at what is now called the absolute zero of temperature.

QUESTION: 20

Assertion (A): Thermodynamic work is path-dependent except for an adiabatic process.

Reason(R): It is always possible to take a system from a given initial state to any final state by performing adiabatic work only.

Solution:

It is not possible to take a system from a given initial state to any final state by performing adiabatic work only.

The assertion is true since in an adiabatic process heat transfer is zero and work is equal to change in internal energy.