KPTCL AE/JE flashcards

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

Transformer EMF equation

RMS induced EMF per turn equals 4.44 times frequency times peak flux, so E = 4.44 f N Φm for a sinusoidal flux of peak value Φm and N turns.

Synchronous speed formula

Ns = 120f/P rpm, where f is supply frequency in hertz and P is the number of poles; slip is (Ns − Nr)/Ns and rotor frequency equals slip times supply frequency.

Thevenin equivalent circuit

Replace a linear network by one voltage source in series with one resistance; the resistance is found by deactivating independent sources while keeping dependent sources active.

Series resonance condition

A series RLC circuit resonates at f = 1/(2π√(LC)); at resonance reactances cancel, impedance equals R, current is maximum, and the power factor is unity.

Target mean strength of concrete

For mix design, target mean strength equals characteristic strength plus 1.65 times the standard deviation, giving the 5 percent failure probability assumed by IS 456.

Flexural formula

Bending stress varies linearly with distance from the neutral axis: M/I = σ/y = E/R, so σ = My/I and section modulus Z = I divided by the extreme fibre distance.

Degree of saturation relation

For a soil, S·e = w·G, where S is degree of saturation, e is void ratio, w is water content and G is specific gravity; dry unit weight is G·γw/(1+e).

Height of instrument method

In levelling, height of instrument equals known reduced level plus backsight; reduced level of a new point equals height of instrument minus its foresight or intermediate sight reading.

Carnot efficiency limit

The maximum efficiency of any heat engine operating between hot and cold reservoirs is 1 − TL/TH, with both temperatures expressed on the absolute Kelvin scale.

Otto cycle efficiency

For the ideal air-standard Otto cycle, efficiency is 1 − 1/r^(γ−1), where r is the compression ratio and γ is the specific heat ratio of the working fluid.

Reynolds number regimes

Reynolds number ρVD/μ classifies pipe flow: below about 2000 it is laminar, between 2000 and 4000 transitional, and above 4000 fully turbulent.

Torsion equation for shafts

For a circular shaft, τ/r = T/J = Gθ/L; shear stress is zero at the axis, maximum at the outer surface, and J equals πd⁴/32 for a solid shaft.

Op-amp virtual short

With negative feedback and ideal input impedance, the differential input voltage is nearly zero, so the inverting node sits at the same potential as the non-inverting node.

Barkhausen oscillation criterion

An oscillator sustains output when the loop gain magnitude equals one and the total loop phase shift is zero or a multiple of 360 degrees at the desired frequency.

Nyquist sampling theorem

A band-limited signal must be sampled at least twice its highest frequency component to allow exact reconstruction; lower rates cause aliasing that anti-alias filters prevent.

Shannon channel capacity

Channel capacity in bits per second is C = B·log2(1 + S/N), where B is bandwidth in hertz and S/N is the linear signal-to-noise power ratio.

De Morgan's theorems

The complement of a product equals the sum of the complements, and the complement of a sum equals the product of the complements; both NAND and NOR are universal gates.

Karnataka formation day

Karnataka was created on 1 November 1956 as Mysore State under the States Reorganisation Act and was renamed Karnataka on 1 November 1973.

Karnataka state symbols

Karnataka's state animal is the elephant, state bird the Indian roller, state tree sandalwood, state flower lotus, and state fish the carnatic carp.

Jog Falls location

Jog Falls lies on the Sharavathi river in Shivamogga district, Karnataka, and is among India's highest plunge waterfalls, formed of four distinct cascades.

Fewer versus less

Use 'fewer' with plural countable nouns and 'less' with uncountable nouns; 'number of' pairs with countables while 'amount of' pairs with uncountables.

Reported speech tense shift

When a reporting verb is in the past, the reported verb usually shifts one tense back, except for universal truths, habitual facts, and unchanged past-tense reporting.

Who versus whom

Use 'who' when the pronoun is the subject of its clause and 'whom' when it is the object of a verb or preposition; 'whose' marks possession.

Kannada alphabet composition

Standard Kannada script has 49 letters: 14 vowels called swaragalu and 35 consonants called vyanjanagalu, with yogavahakas handling conjunct and half sounds.

Kannada literary gems

Pampa, Ranna and Ponna are honoured as the three gems of Kannada literature; Kavirajamarga, dated around 850 CE, is the earliest available Kannada work.

Kannada language structure

Kannada is a Dravidian, agglutinative language with subject-object-verb order; verbs agree with the subject in person, number and gender, and nouns take eight cases.

Compound interest formula

Amount equals principal times (1 + R/100) raised to the number of years, with interest compounded annually; compound interest is the amount minus the principal.

Successive percentage change

Two successive changes of a percent and b percent produce a net change of a + b + ab/100 percent, where the signs of a and b carry increases or decreases.

Combined work formula

If A alone finishes work in x days and B alone in y days, working together they finish it in xy/(x + y) days, assuming independent uniform rates.

Alligation rule

To mix ingredients priced cheaper and dearer to obtain a mean price, the quantity ratio is (mean − cheaper) to (dearer − mean).

Syllogism validity test

A conclusion follows only if it is true in every possible Venn diagram consistent with the premises; a single counterexample diagram makes it invalid.

Calendar odd days

An ordinary year has 1 odd day and a leap year 2; 100 years give 5 odd days and 400 years give none, which fixes the day for any given date.