Q101.The second order partial differential equation ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ 2 2 2 2 2 2 z z z z – 2sinx – cos x – cos x = 0 x x y y y is
Correct answer: Hyperbolic for all values of x, y
Q102.The Fourier transform of 2 x – 2 e is
Correct answer: 2 s – 2 2 e π
Q103.-1 2 s –1 L s – 6s +13 is equal to
Correct answer: () 3x e cos2x sin 2x +
Q104.The curve, for which () ∫ π/2 2 0 y' + 2xyy' dx subjected to y (0) = 1, y π 2 = 1 is extremised, is
Correct answer: y = sinx + cosx
Q105.Inner product of tensors Aij and Bhk will be a mixed tensor of the type
Correct answer: (1, 1)
Q106.General solution x = z (x, y) of the partial differential equation y2 zp + x2 zq = xy2, is
Correct answer: () 3 3 2 2 F x y,x z 0 − − =
Q107.The value of L–1 –1/s e s is
Correct answer: J0 ( )/2 t
Q108.If φ1 and φ2 are arbitrary functions, then the solution of the partial differential equation γ = a2 t, is
Correct answer: () () 1 2 z y ax y ax = φ + + φ −
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q109.An external of the functional [ ] () 3 + ∫ ' 2 y 0 I y(x) = e dx,y(0) = 0,y(2)=1, is-
Correct answer: Strong minimum on x y 2 =
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q110.The condition that ∂ ∂ d f f – = 0 dx y' y for the functional [ ] () ∫ 2 1 x I y(x) = f x,y,y' dx to have a stationary value is-
Correct answer: only necessary
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q111.The extremal of the functional () ∫ 1 2 0 V[y(x)] = y' +12xy dx,y(0) = 0, y(1)=1, represents-
Correct answer: nodal cubic curve
EnglishUPPSC GDC 2021 UPPSC Polytechnic Lecturer 2021 (I)
Q112.If F(x,y,y') is independent of x, then Euler's equation for the functional () ∫ 2 1 x F x,y,y' dx reduces to-
Correct answer: F–y'Fy'=c
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q113.The Euler equation for the functional () () z ∫∫ 2 2 D x y I z x,y = + z dxdy satisfy-
Correct answer: Laplace equation
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q114.The extremals of the functional ∫ 2 1 θ 2 2 '2 θ r + r dθ where () dr r = r θ,r' =, dθ is given by-
Correct answer: 1 2 rsin C rcos C θ = θ +
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q115.The extremals of the functional () ∫ π 2 2 2 5 0 I = y'' – y + x dx, () () y 0 = 0,y' 0 = 1 π 1 y' = 4 2 is-
Correct answer: y=sinx
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q116.An extremals to the functional () () () ∫ b 2 a V y x = 1+ y' x dx
Correct answer: The straight line connecting (a,y(a)) and (b,y(b))
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q117.The functional () ∫ π '2 2 2 0 y – y + 2xy dx with () π y 0 = 0,y = 0 2 can be extremized on the curve-
Correct answer: y x – sin x 2 π =
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q118.How many extremals s are possible for the extremals () ∫ 2 1 2 0 d y I y x = + y dx,y(0) = 1, dx () () () y 1 = –1,y' 0 = 1,y' 1 = 1?
Correct answer: None of the above
EnglishUPPSC Polytechnic Lecturer 2021 (I)
Q119.The variation problem of eternizing the functional [ ] ∫ 2 2π 2 0 dy I y(x) = – y dx,y(0) = 1, dx y(2π) = 1 has-
Correct answer: An infinite many solutions
EnglishUPPSC Polytechnic Lecturer 2021(II)
Q120.The Eigen values of the homogeneous integral equation φ(x) = φ ∫ 2 1 λ xt + (t) xt dt is –
Correct answer: () 1 17 265 2 ±