BSF Tradesman flashcards

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

Preamble amendment

The Preamble has been amended only once, by the 42nd Amendment in 1976, which added the words socialist, secular and integrity to the original text.

RBI establishment

The Reserve Bank of India was set up in 1935 and nationalised in 1949. It issues currency notes, runs monetary policy and supervises banks.

Chandrayaan-3 landing

In August 2023 India's Chandrayaan-3 made a soft landing near the Moon's south pole, making India the first country to land in that region.

National animal of India

The tiger is India's national animal, the peacock is the national bird, the Ganga the national river, and the lotus the national flower.

Opposite letter pairs

In the English alphabet, letters opposite each other sum to 27: A pairs with Z, B with Y, and C with X. This solves many coding questions.

Syllogism validity rule

A conclusion is valid only if it is true in every possible Venn diagram of the premises. Two particular premises never yield a definite conclusion.

Row position formula

For a person in a row of n people, the position from the left plus the position from the right equals n plus one.

Blood relation tree

Draw generations on vertical lines and siblings or spouses on horizontal lines. Mark gender with symbols so 'only son' and 'only daughter' clues become clear.

Successive percentage change

Two successive changes of a percent and b percent give a net change of a plus b plus ab divided by 100, measured in percent.

Simple interest formula

Simple interest equals principal times rate times time divided by 100. It is calculated on the original principal only, not on accumulated interest.

Work together formula

If A alone takes a days and B alone takes b days, working together they finish in ab divided by (a plus b) days.

Average speed formula

For equal distances travelled at speeds x and y, average speed is 2xy divided by (x plus y), not the simple mean of the two speeds.

Cylinder volume

The volume of a cylinder is pi times radius squared times height. The volume of a cone with the same base and height is one third of that.

Hindi gender ending

Hindi nouns ending in 'aa' are usually masculine and those ending in 'ii' usually feminine, but exceptions such as 'paani' must be memorised.

Hindi case markers

The main Hindi postpositions are ne for the agent, ko for the object, se for instrument, ka/ke/kii for possession, and mein for location.

Subject-verb agreement

A singular subject takes a singular verb. With either-or and neither-nor, the verb agrees with the subject nearer to it.

Articles a and an

Use 'a' before consonant sounds and 'an' before vowel sounds, so 'an hour' and 'a university' are correct because sound, not spelling, decides.

Ohm's law

Voltage equals current times resistance. Power equals voltage times current, also written as current squared times resistance.

Micrometer least count

The least count of a micrometer equals the screw pitch divided by the number of divisions on the thimble, commonly 0.5 mm divided by 50, giving 0.01 mm.

Domestic supply values

Indian domestic supply is 230 volt single phase at 50 hertz. Three-phase supply is 415 volt, with 120 degrees between phases.

Mortar mix ratios

Cement to sand ratio 1:6 is used for brickwork mortar and 1:3 for plaster. Bricks are soaked before laying so they do not absorb water from the mortar.

Four-stroke engine cycle

The four strokes are intake, compression, power and exhaust. One complete cycle takes two revolutions of the crankshaft.

Electrode code 6013

In a 6013 electrode, 60 means 60,000 psi minimum tensile strength, 1 means all-position welding, and 3 identifies the coating and current type.

Fire classes

Class A is solid combustibles, B flammable liquids, C gases, and D metals. Electrical fires need carbon dioxide or dry powder, never water.

Lockout tagout

Switch off and isolate the supply, fit a lock and tag, and prove the circuit dead with a tester before any work begins.

Electrical shock first aid

First switch off the supply or move the victim with a dry insulating object. Never touch a victim still in contact with live parts, then give CPR if needed.

Hacksaw blade direction

A hacksaw blade is fitted with the teeth pointing forward, away from the handle, so that cutting happens on the forward stroke.

Memory units

One byte is eight bits. One kilobyte is 1024 bytes, one megabyte is 1024 kilobytes, and one gigabyte is 1024 megabytes.

RAM versus ROM

RAM is volatile working memory that is cleared when power is switched off. ROM is non-volatile and stores firmware such as the BIOS.

DNS function

The Domain Name System converts human-readable website names into numerical IP addresses so that browsers can reach the correct server.

Email Cc and Bcc

Cc sends a visible copy to other recipients. Bcc sends a hidden copy, so Bcc recipients are not shown to anyone else on the message.

UPI payment

Unified Payments Interface transfers money between bank accounts using a virtual payment address. A one-time password confirms the transaction and must never be shared.