### Introduction to Energy Transfer

• Investigate and understand states and forms of energy and how energy is transferred and transformed.

• Investigate and understand temperature scales, heat, and heat transfer.

An energy transfer or ’energy exchange’ from one system to another is said to occur when an amount of energy crosses the boundary between them, thus increasing the energy content of one system while decreasing the energy content of the other system by the same amount.

### Solved Example:

#### 70-0-01

Clapeyron equation is a relation between:

Solution:
Chaperon equation is a relation between temperature, pressure, specific volume and enthalpy. It is used to estimate the vapor pressure at another temperature, if the vapor pressure is known at some temperature and if the enthalpy of vaporization is known.

Correct Answer: D

### Solved Example:

#### 70-0-02

Clapeyron equation is applicable for registration at:

Correct Answer: A

### Solved Example:

#### 70-0-03

Critical pressure of a liquid is the pressure:

Correct Answer: A

### Solved Example:

#### 70-0-04

Critical temperature is the temperature above which:

Correct Answer: A

### Solved Example:

#### 70-0-05

The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents:

Correct Answer: B

### Solved Example:

#### 70-0-06

Short horizontal lines on pressure-enthalpy chart show:

Correct Answer: A

### Solved Example:

#### 70-0-07

On the pressure-enthalpy diagram, condensation and desuperheating is represented by a horizontal line because the process:

Correct Answer: D

### Solved Example:

#### 70-0-08

Super heating in a refrigeration cycle:

Correct Answer: B

### Solved Example:

#### 70-0-09

For proper refrigeration in a cabinet, if the temperature and vapour pressure difference between cabinet and atmosphere is high, then:

Correct Answer: C

### Solved Example:

#### 70-0-10

Vertical lines on pressure-enthalpy chart show constant:

Correct Answer: C

### Solved Example:

#### 70-0-11

If a certain amount of dry ice is mixed with same amount of water at 80$^\circ$C, the final temperature of mixture will be:

Correct Answer: B

### Solved Example:

#### 70-0-12

One watt is equal to:

Correct Answer: A

### Solved Example:

#### 70-0-13

For which of the following substances, the internal energy and enthalpy are the functions of temperature only:

Correct Answer: D

### Solved Example:

#### 70-0-14

The specific heat of air increases with increase in:

Correct Answer: A

### Solved Example:

#### 70-0-15

The energy of molecular motion appears as:

Correct Answer: A

### Solved Example:

#### 70-0-16

The unit of universal gas constant is:

Correct Answer: D

### Solved Example:

#### 70-0-17

Calorie is a measure of:

Correct Answer: B