DRDO CEPTAM STA-B common mistakes
DRDO CEPTAM STA-B · Understand the traps and how to avoid them.
Spends six to eight minutes trying to crack the first five-question seating-arrangement or multi-condition puzzle set, then rushes the remaining reasoning items at under 30 seconds each.
Once a set is opened and two of its five sub-parts are solved, quitting feels like wasting the work already done. The sunk-cost effect is strongest in puzzle sets because partial progress is visible, whereas an abandoned single-line analogy feels costless.
What to do instead
Run a deliberate two-pass order. Pass one: only single-line items (analogy, odd-one-out, number classification, direction sense, one-word coding). Open a puzzle set only if a first 20-second read yields a fixed seat, a definite pair, or a direct placement. Otherwise mark it and return after all singles are attempted.
Solves blood-relation and direction-sense questions entirely in his head, then re-derives the whole chain from the start when the fourth statement contradicts the third.
These items look short enough to hold in working memory, so no paper is used. When the chain has more than three links, or uses pronouns like 'my father's only sister's son', silent tracking breaks down and the candidate cannot tell which earlier step was wrong.
What to do instead
Force a diagram on every blood-relation item: symbols for male/female and a line for each generation, working outward from a definite anchor person, never restarting from the top. For direction sense, mark the start point as a dot, label every turn as a compass arrow, and write the final displacement separately from the total distance walked.
Works out 37% of 1,240 by full long multiplication and carries it to two decimal places, even when the four options are 450, 460, 470 and 480.
School habits reward exactness, and approximation is never deliberately trained. Without a memorised fraction table, the candidate does not see that 37% of 1,240 must lie between 1/3 and 3/8 of 1,200, so estimation feels riskier than brute force.
What to do instead
Drill the percentage-fraction table until it is automatic (12.5% = 1/8, 16.67% = 1/6, 37.5% = 3/8, 62.5% = 5/8). Before computing anything, look at the option spread: if options are far apart, estimate and pick; compute exactly only when two options sit within one unit of each other.
Substitutes a speed given in km/h into a formula that mixes time in seconds and distance in metres, gets a number, and then chooses the option that matches the un-converted value.
Formulas are memorised as symbol strings (Speed = Distance/Time) without attaching units to the symbols. Unit conversion is treated as trivia rather than as part of the arithmetic, so the mistake produces a plausible-looking number rather than an obviously wrong one.
What to do instead
Write the unit beside every figure at the moment of copying it into the rough sheet. Convert everything to one system first (km/h × 5/18 = m/s) and only then substitute. As a final check, sanity-check the magnitude: a train crossing a platform should not take 4 seconds or 40 minutes.
Answers a question on the unit of force as 'newton per metre', or the unit of pressure as 'newton', and states that weight stays the same on the Moon.
Class 9 definitions were read once and never contrasted with each other, so quantities that share vocabulary get merged. Weight and mass are used interchangeably in everyday speech, and pressure's definition (force/area) is remembered as a formula rather than as a unit.
What to do instead
Build a single one-page table with columns: quantity, SI unit, symbol, scalar or vector, one-line definition. Revise only the confusable pairs (mass vs weight, force vs pressure vs work, heat vs temperature) and test yourself by covering the unit column. Add the Moon-weight point as a worked example under weight.
Confuses baking soda with washing soda and quicklime when a question asks which substance is used to soften hard water or to make bread rise, and swaps atomic number with mass number.
Everyday names are learnt in one list and chemical formulae in another, and they are rarely cross-linked. Because the names sound similar and all are white powders, recall without a distinguishing attribute collapses under exam pressure.
What to do instead
Make three-column cards: common name, formula, one defining use or behaviour (effervescence, water of crystallisation, exothermic slaking). Say the distinguishing attribute aloud with each card. For atomic number versus mass number, anchor on one concrete element such as sodium (Z = 11, A = 23).
Prepares general awareness entirely from banking- and SSC-style monthly current-affairs capsules - appointments, schemes, sports - and cannot identify recent missile trials, DRDO laboratory names, or indigenously developed defence systems.
Default coaching material is built for the largest exams, so it reflects their topic mix. The candidate assumes 'current affairs' is one uniform block and does not check which slice the recruiting organisation actually cares about.
What to do instead
Build a defence-science current-affairs sheet covering the last 8 to 12 months from DRDO, ISRO and defence ministry releases: for each item record name, type (ballistic or cruise, for example), and the laboratory or agency involved. Keep it to one page and revise weekly rather than reading a 200-page compilation.
Mixes up similar-sounding static-science facts - names Bhaskara instead of Aryabhata as India's first satellite, or labels a cruise missile as ballistic purely because the name sounds familiar.
Facts are stored as loose name associations without a differentiating tag, so any two names from the same period collapse into one. The retrieval cue in the exam question is the name, not the attribute, and the name is exactly what is missing.
What to do instead
Store every fact with one distinguishing tag and revise in contrasting pairs: Aryabhata (1975, first) versus Bhaskara (1979, remote sensing); ballistic (exits the atmosphere, follows a parabola) versus cruise (atmospheric, powered flight). Ten paired contrasts per week is more effective than reading long lists.
Agrees the verb with the nearest noun - writing 'The list of items were long' or selecting 'were' in 'One of the boys ___ present' - because the sentence sounds correct read aloud quickly.
Reading by ear follows the rhythm of the last noun heard, and the spoken convention in Indian English often reinforces the wrong form. The candidate is not testing the noun phrase, only listening to the sentence.
What to do instead
Underline the head noun, cross out every prepositional phrase between the subject and the verb, then choose the verb. Drill the fixed patterns separately: 'one of + plural noun + singular verb', 'each of', 'a number of + plural' versus 'the number of + singular'. Do 20 sentences a day with the phrases crossed out.
Chooses a comprehension option because it contains a word visible in the passage but which answers a slightly different question, or misses the 'EXCEPT' and 'NOT' in the stem and marks the one true statement.
Under time pressure the candidate matches surface keywords rather than reading the stem, and negation words are lower in visual salience than content words like 'scientist' or 'laboratory'.
What to do instead
Read the question stem before the options and circle any negation word. For each option, locate the exact sentence that supports or contradicts it, and reject options whose claim is merely 'not stated'. For inference questions, explicitly forbid yourself from choosing an option that is true in real life but absent from the passage.