CSIR NET Physical Sciences Part A Syllabus

In an alphabet series, how do you handle a backward (reverse) sequence such as Z, X, V, T, ?

Recognize the step is $-2$ positions each time: Z→X→V→T→R. The next term is R.

In 'Symbols and Notations' questions, how should given symbol definitions (e.g. $P + Q$ means 'P is the father of Q') be interpreted?

Each symbol is assigned an artificial meaning given in the question; you must substitute the stated meaning for each symbol and build the relationship exactly as defined, ignoring the symbol's normal arithmetic meaning.

In a mathematical-operation substitution problem, if $+$ means $\times$, $-$ means $+$, $\times$ means $\div$, and $\div$ means $-$, evaluate $6 + 2 - 4 \times 2$.

Substitute: $6 \times 2 + 4 \div 2 = 12 + 2 = 14$. (Apply BODMAS after substitution.)

What order of operations (BODMAS/PEMDAS) governs simplification problems?

Brackets, Orders (powers/roots), Division and Multiplication (left to right), then Addition and Subtraction (left to right).

Simplify: $\frac{2}{3} + \frac{1}{6}$.

Common denominator 6: $\frac{4}{6} + \frac{1}{6} = \frac{5}{6}$.

In 'Similarities and Differences' reasoning, what distinguishes a similarity-based pairing from a difference-based one?

A similarity pairing groups items by a shared common property; a difference (or contrast) pairing identifies items that differ or are opposites. The task is to detect which relation (common feature vs. distinguishing feature) governs the set.

What is the general method for solving a number series?

Examine the differences (or ratios) between consecutive terms to detect a pattern—arithmetic (constant difference), geometric (constant ratio), squares, cubes, primes, or alternating patterns—then extend it.

Find the next term: 2, 6, 12, 20, 30, ?

Differences are 4, 6, 8, 10, so the next difference is 12: $30 + 12 = 42$. (Terms follow $n^{2}+n$.)

Find the next term in the geometric series: 3, 6, 12, 24, ?

Each term is multiplied by 2 (constant ratio $r = 2$): $24 \times 2 = 48$.

Find the missing term: 1, 4, 9, 16, 25, ?

These are perfect squares $n^{2}$: $1, 4, 9, 16, 25, 36$. The next term is $36 = 6^{2}$.

Find the next term: 1, 1, 2, 3, 5, 8, ?

13. This is the Fibonacci series where each term is the sum of the two preceding terms: $5 + 8 = 13$.

In blood-relation problems, what relation is 'my father's only son'?

It refers to the speaker himself (oneself), assuming the speaker is male, since the father's only son must be the speaker.

In a blood-relation puzzle, how is 'my mother's brother' related to me?

He is my maternal uncle.

In blood relations, who is 'the daughter of my grandfather's only son'?

My grandfather's only son is my father, so his daughter is my sister (or myself if I am female).

What is the key strategy for solving complex blood-relation statements?

Draw a family-tree diagram using standard symbols (e.g. + for male, − for female, horizontal line for spouse/siblings, vertical line for parent-child) and trace the relationship step by step from the speaker.

In linear arrangement (seating) problems facing the same direction, how are left and right defined?

Left and right are taken from the perspective of the persons being seated (not the observer). For a row facing North, a person's right is toward the East side and left toward the West side.

In a circular arrangement where all people face the centre, how do left and right relate to clockwise/anticlockwise?

For people facing the centre, the right hand points anticlockwise and the left hand points clockwise. (If they face outward, this reverses.)

In 'Statements and Conclusions' questions, what does it mean for a conclusion to 'follow'?

A conclusion follows only if it is logically and necessarily derivable from the given statement(s) alone, without using any outside knowledge or assumptions.

In 'Statement and Assumptions' questions, what is an assumption?

An assumption is something taken for granted or implied (not stated) that the speaker must believe to be true for the statement to make sense. It is the unstated supposition underlying the statement.

In 'Statement and Arguments', how do you judge whether an argument is 'strong'?

A strong argument is directly related to the question, addresses a real and important aspect, and is logically substantial; a weak argument is trivial, ambiguous, not directly related, or based on a minor/improbable assumption.

What is the purpose of a Data Sufficiency question?

To determine whether the information given in the statements is sufficient to answer the question—NOT to actually compute the final answer. You decide if each statement alone, both together, or neither is enough.

State the standard 5-option answer scheme used in Data Sufficiency questions.

(A) Statement 1 alone is sufficient but not 2; (B) Statement 2 alone is sufficient but not 1; (C) both together are sufficient but neither alone; (D) each alone is sufficient; (E) both together are still insufficient.

In Data Sufficiency, why should you avoid carrying assumptions from Statement 1 when evaluating Statement 2?

Each statement must first be tested independently. Mixing information from Statement 1 into the evaluation of Statement 2 leads to wrongly concluding a statement is sufficient when it is not.

What is non-verbal reasoning?

Reasoning based on visual figures, shapes, and patterns rather than words—including series completion, analogies, classification, mirror/water images, paper folding, and embedded figures, where you detect rules from diagrams.

In non-verbal reasoning, how is a mirror image of a figure formed about a vertical mirror?

The figure is laterally inverted: left and right are interchanged while top and bottom remain unchanged (a left-right flip across the vertical axis).

How does a water image (reflection) of a figure differ from a mirror image?

A water image is an upside-down reflection about a horizontal axis—top and bottom are interchanged while left and right stay the same—as if reflected in water below the object.

In a paper-folding-and-punching (visual ability) problem, how do you find the pattern of holes when the paper is unfolded?

Each fold creates a line of symmetry; on unfolding, every punched hole is reflected across each fold line, so the number of holes doubles with each fold and they appear symmetrically placed about the fold axes.

In graphical analysis, what does the slope of a line on a distance–time graph represent?

The slope equals speed (velocity): $\text{slope} = \frac{\Delta \text{distance}}{\Delta \text{time}}$. A steeper line means greater speed; a horizontal line means the object is at rest.

In a pie chart used for data analysis, how do you convert a sector's central angle into its percentage of the total?

Percentage $= \dfrac{\text{central angle}}{360^{\circ}} \times 100\%$. For example, a $90^{\circ}$ sector represents $\frac{90}{360}\times100 = 25\%$ of the total.

In data analysis, how is percentage change between an old value and a new value calculated?

$\text{Percentage change} = \dfrac{\text{New value} - \text{Old value}}{\text{Old value}} \times 100\%$; a positive result is an increase, a negative result a decrease.

How do you compute the arithmetic mean (average) of a data set, often needed in data-analysis problems?

$\text{Mean} = \dfrac{\text{Sum of all observations}}{\text{Number of observations}} = \dfrac{\sum_{i=1}^{n} x_i}{n}$.