JKSSB JE Civil flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Target mean strength

In IS concrete mix design, f'ck = fck + 1.65s, where s is the assumed standard deviation for the grade. It ensures the specified characteristic strength is met with acceptable probability.

Slump test

A workability test using a standard cone; the vertical settlement of the concrete is measured in mm. It suits normal mixes but is unreliable for very dry or very wet mixes.

Duty and delta

Duty is the area of land irrigated per unit discharge (ha per cumec); delta is the depth of water required over the crop period. Their product relation is Duty × Delta = 8.64.

Neutral axis depth factor

In working-stress design, k = mσcbc/(mσcbc + σst), where m is the modular ratio. It locates the neutral axis depth as k times the effective depth.

Terzaghi bearing capacity

For a strip footing, qu = cNc + γDfNq + 0.5γBNγ. Safe bearing capacity is qu divided by a factor of safety, usually 2.5 to 3.

Manning equation

Open channel velocity V = (1/n)R^(2/3)S^(1/2), where n is roughness, R is hydraulic radius (area/perimeter), and S is bed slope.

Article 370

The constitutional provision that gave Jammu and Kashmir special autonomous status. It was abrogated on 5 August 2019, and J&K became a Union Territory on 31 October 2019.

Wular Lake

A large freshwater lake in Bandipora district of Kashmir, fed by the Jhelum. It is regarded as the largest freshwater lake in India and is a Ramsar site.

Fundamental Duties

Duties listed in Article 51A of the Constitution, added by the 42nd Amendment in 1976 on the recommendation of the Swaran Singh Committee. They are not directly enforceable.

NITI Aayog

The policy think tank that replaced the Planning Commission in 2015. It issues three-year action agendas and seven-year strategy papers and does not allocate plan funds.

Syllogism conversion

Valid immediate inferences: All A are B gives Some B are A; Some A are B gives Some B are A; No A is B gives No B is A. All A are B never converts to All B are A.

Clock angle formula

The angle between the hands is |30H − 5.5M| degrees, where H is the hour and M the minutes. If the result exceeds 180°, take 360° minus that value.

Odd days in 100 years

100 years contain 5 odd days, 200 years 3, 300 years 1, and 400 years 0. These values are used to find the day of the week for a given date.

Direction after turns

From North, a right turn faces East and a left turn faces West; each turn is 90°. Net displacement after moves is found by Pythagoras on the north-south and east-west legs.

Total from two ranks

When a person ranks r1 from the top and r2 from the bottom, the total number of persons is r1 + r2 − 1, because the person is counted in both ranks.

CI minus SI for two years

For two years, the difference between compound and simple interest equals P(R/100)². For three years it is P(R/100)²(3 + R/100).

Alligation rule

To mix two ingredients at prices c and d to get mean price m, the ratio of cheaper to dearer quantities is (d − m) : (m − c).

Train crossing a platform

A train of length L crossing a platform of length P at speed v takes (L + P)/v. Crossing a pole takes only L/v.

Average speed equal distances

For two equal distances covered at speeds x and y, the average speed is 2xy/(x + y), the harmonic mean, not the arithmetic mean of the speeds.

HCF and LCM relation

For any two positive integers, HCF × LCM equals the product of the numbers. This lets you find one value when the other three are known.

Sum of first n squares

The sum 1² + 2² + … + n² equals n(n + 1)(2n + 1)/6. The sum of the first n natural numbers is n(n + 1)/2.

Successive percentage change

An increase of a% followed by a decrease of b% gives a net change of a − b − ab/100 percent. Two successive 20% changes leave 96% of the original value.

Subject-verb with either/or

With 'either … or' and 'neither … nor', the verb agrees with the subject nearer to it. Words like each, every, and everyone take a singular verb.

Since versus for

'Since' is used with a point of time (since 2019) and 'for' with a duration (for three years). Both typically pair with perfect tenses.

Affect versus effect

'Affect' is usually a verb meaning to influence; 'effect' is usually a noun meaning a result. Confusing them is a common error-spotting trap.

Passive voice formation

The object becomes the subject, the verb becomes a form of be plus the past participle, and the agent follows 'by'. Only transitive verbs can be made passive.

One-word substitution examples

Ephemeral means short-lived, ubiquitous means present everywhere, meticulous means very careful, and ambiguous means open to more than one meaning.

Idiom: eleventh hour

'At the eleventh hour' means at the last possible moment. 'To beat about the bush' means to avoid coming to the main point.

Modular brick size

IS 1077 standard brick is 190 × 90 × 90 mm; with mortar the nominal size is 200 × 100 × 100 mm, giving 500 bricks per cubic metre of masonry.

Rise and fall method

In levelling, rise equals backsight minus foresight; the next reduced level is the previous RL plus rise or minus fall. The arithmetic check is ΣBS − ΣFS = last RL − first RL.

Camber and superelevation

Camber is the cross slope for drainage, typically 2–3% on flexible pavements. Superelevation e = v²/(127R) for design speed v in km/h and radius R in metres.

BOD versus COD

BOD measures oxygen consumed by microorganisms over five days at 20 °C. COD is a chemical measure of oxidisable matter and is always higher than BOD.