(SEM VIII) THEORY EXAMINATION 2018-19 NON DESTRUCTIVE TESTING

NON-DESTRUCTIVE TESTING (NME-065)

According to the uploaded question paper 

The examination is divided into three sections — A, B, and C. Each section evaluates different levels of understanding, beginning with basic definitions and moving toward detailed theoretical explanations and practical applications of Non-Destructive Testing (NDT) methods.

Below is a detailed explanation of each section in proper descriptive format.

Section A – Basic Concepts and Definitions (20 Marks)
 

Section A consists of ten compulsory short-answer questions, each carrying two marks. This section checks your understanding of fundamental principles and terminology used in Non-Destructive Testing.

The questions generally focus on definitions and basic theoretical concepts such as devices used in visual inspection, contrast ratio and contrast sensitivity, dwell time in penetrant testing, skin effect in eddy current testing, nature of radiation, Bragg’s Law, attenuation, Snell’s Law, types of probes, and Lenz’s Law.

Even though the answers are short, they require conceptual clarity. For example, when defining attenuation, you should explain how radiation intensity decreases as it passes through a material. Similarly, when explaining skin effect, you should describe how alternating current tends to concentrate near the surface of a conductor.

This section ensures that you understand the core scientific principles behind different NDT techniques.

Section B – Detailed Explanation and Numerical Application (30 Marks)
 

Section B requires you to attempt any three questions, each carrying ten marks. This section tests your ability to explain NDT techniques in detail and apply theoretical concepts in numerical problems.

The questions typically include topics such as types of defects in casting, welding, and forging that can be detected only by NDT methods; properties and classification of penetrants used in liquid penetrant testing; numerical problems based on Bragg’s Law; ultrasonic testing with neat sketches, applications, advantages and disadvantages; and eddy current testing for tube inspection and fatigue crack detection.

In this section, you are expected to write structured answers with clear explanations and diagrams wherever required. For example, when explaining ultrasonic testing, you should describe the working principle based on reflection of high-frequency sound waves, explain pulse-echo method, and mention its industrial applications. If solving numerical problems, you must show formula substitution and final results clearly.

This section evaluates your understanding of practical inspection techniques and your ability to connect theory with real-world industrial applications.

Section C – Advanced Concepts and Technical Analysis (50 Marks)
 

Section C carries the highest weightage and requires you to attempt one part from each question. This section focuses on advanced theoretical concepts and practical implementation of NDT methods.

The topics include machine vision technology in visual inspection, magnetization methods in magnetic particle testing, standards in liquid penetrant testing, Rayleigh and Compton scattering in radiation physics, ultrasonic testing in medical diagnosis, ultra-sonography, factors affecting eddy current testing, and types of probes used in eddy current testing.

Here, the examiner expects deep explanation supported by diagrams and technical reasoning. For instance, when discussing Rayleigh and Compton scattering, you should explain how electromagnetic radiation interacts with matter and how energy transfer occurs. Similarly, while explaining eddy current probes, you should describe surface probes, bobbin probes, and internal probes with their applications.

This section tests analytical ability, conceptual depth, and understanding of industrial and medical applications of NDT techniques.

Overall Structure and Preparation Strategy
 

The paper is structured progressively. Section A checks your basic understanding of definitions and laws. Section B tests detailed explanation and numerical problem-solving ability. Section C evaluates advanced technical knowledge and application-based understanding.

To prepare effectively:

Strengthen your basic definitions and scientific laws for Section A.

Practice diagram-based explanations and numerical problems for Section B.

Study advanced inspection methods and radiation physics carefully for Section C.