ENT 342 exam II

  1. The square root of -1 is
    the symbol i or j
  2. i*i or j*j is
    -1
  3. i^3 or j^3 is
    -j
  4. i^4 or j^4 is
    1
  5. A complex number is
    like a 2D vector
  6. Complex numbers
    are frequently used in electrical engineering
  7. The number (3+j4) is an example of a _______ number
    complex
  8. The real part of 3+j4 is
    3
  9. The imaginary part of 3+j4 is
    4
  10. The magnitude of 3+j4 is
    5
  11. The angle of 3+j4 is
    53.13 deg
  12. The sum of 3 and j4 is
    3+j4
  13. The magnitude of the sum of 3 and j4 is
    5
  14. The angle of the sum of 3 and j4 is
    53.13 deg or 0.927 rad
  15. exp(1) is
    2.71828
  16. exp(j*pi) is
    -1
  17. exp(-j*pi) is
    -1
  18. exp(-j*pi/2) is
    -j
  19. The sum of 3 and j4 is
    • exp(0.927j)*5
    • 5*exp(0.927j)
    • both of these
  20. Complex numbers can be
    • all of these
    • multiplied and divided
    • added and subtracted
    • raised to powers
    • placed in matrices
  21. exp(j*z) is the same as
    cos(z)+j*sin(z)
  22. sin(z), cos(z), tan(z), ln(z), log(z) _____ when z is a complex number
    are defined
  23. AC voltage of 5*exp(j53.13 deg) has an amplitude of
    5 volts
  24. AC voltage of 5*exp(j53.13 deg) has an phase of
    53.13 degrees
  25. Video H342510 has an error at time 4:56 where the ramp function is missing.
    true
  26. The mathematically rigorous version of a complex number in polar form is
    (exp(-i*G)*A) where G is in radians
  27. A complex number in polar form looks like (exp(-i*G)*A) if G is expressed in
    radians
  28. A complex number in polar form looks like (A/_G) if G is expressed in
    degrees
  29. The poles of F(s)=N(s)/D(s) are also the roots of the polynomial:
    D(s)
  30. The possible number of different types of poles of F(s) in this course is
    3
  31. The inverse Laplace Transform of F(s) contains f(t)=A*exp(K*t)*sin(w*t+M) for each
    complex conjugate pair of poles
  32. The inverse Laplace Transform of F(s) contains f(t)=A*t*exp(-H*t) + C*exp(-H*t) for each
    pair of repeating real poles
  33. The inverse Laplace Transform of F(s) contains a term f(t)=A*exp(-B*t) for each
    pair of repeating real poles
  34. The inverse Laplace Transform of F(s) contains a term f(t)=A*exp(-B*t) for each
    non-repeating real pole
  35. Can M be expressed in degrees in f(t)=A*exp(K*t)*sin(w*t+M)?
    frequently is, but never in a calculation
  36. The radian phase shift of f(t)=A*exp(K*t)*sin(w*t+M) is
    M
  37. The radian/second frequency of f(t)=A*exp(K*t)*sin(w*t+M) is
    w
  38. The function f(t)=A*exp(K*t)*sin(w*t+M) is called
    sinusoidal modulated by an exponential function
  39. The function f(t)=A*t*exp(-H*t) + C*exp(-H*t) is called
    exponential plus another exponential component modulated by a ramp
  40. The function f(t)=A*exp(-B*t) is called
    exponential
  41. If B is negative in the function f(t)=A*exp(-B*t), then the time constant
    does not exist, because the function is unstable
  42. The time constant in f(t)=A*exp(-K*t)*sin(w*t+M) is 1/K.
    1/K
  43. In this stable function, f(t)=A*exp(K*t)*sin(w*t+M), K is
    always negative
  44. The time constant of both terms in f(t)=A*t*exp(-H*t) + C*exp(-H*t)
    1/H
  45. The time constant in f(t)=A*exp(-B*t) is
    1/B
  46. Delta functions closely approximate real-world situations.
    true
  47. Delta functions are
    theoretical and extremely practical
  48. . 6*delta(t) has a height of _____ and width of _____ and an area of ____.
    infinity, zero, 6
  49. A unit delta function has a height of _____ and width of _____ and an area of ____.
    infinity, zero, one
  50. A delta function has a height of _____ and width of _____.
    infinity, zero
  51. If F(s) is a constant, the inverse Laplace transform f(t) is
    a delta function
  52. Long division can be performed on polynomials by the TI-89 using the function
    propFrac(N(x)/D(x))
  53. Proper N2(s)/D(s) in F(s)=P(s)+N2(s)/D(s), and N2(s) is a
    function of s
  54. Proper N2(s)/D(s) in F(s)=P(s)+N2(s)/D(s), and P(s)
    is a constant or a function of s
  55. Proper N2(s)/D(s) in F(s)=P(s)+N2(s)/D(s) is derived from improper F(s)=N(s)/D(s) by dividing
    D(s) into N(s)
  56. For improper F(s)=N(s)/D(s), proper F(s)=P(s)+N2(s)/D(s) is where the degree of ___ is less than the degree of ____.
    N2(s), D(s)
  57. F(s) = N(s) / D(s) is improper when the degree of ___ is greater or equal to the degree of ____.
    N(s), D(s)
  58. The improper fraction 13/4 can be made proper by division and is equivalent to
    3 plus 1/4
  59. 1/j
    -j
  60. The impedance in Ohms of a capacitor is _____ Ohms.
    • 1/(jwC)
    • -j/(wC)
    • all of these
    • (1/C)/(jw)
  61. The impedance in Ohms of an inductor is _____ Ohms.
    jwL
  62. The impedance in Ohms of a resistor is _____ Ohms.
    R
  63. Use the s-domain instead of the jw-domain, because the s-domain yields
    both transient and steady state solutions
  64. Use the jw-domain instead of the s-domain
    only in steady state conditions
  65. To transform from the s-domain to the jw-domain, replace s with j*w.
    true, it is that easy.
  66. Derivative in the time domain is equivalent to ______ in the s-domain.
    multiplication by s
  67. The Laplace transform of i'(t)=(d/dt)i(t) is
    s*I(s)
  68. The Laplace transform of v'(t)=(d/dt)v(t) is
    s*V(s)
  69. IV relationship for a resistor is _____ in the time domain.
    an algebraic equation
  70. IV relationship for an inductor or capacitor is _____ in the time domain.
    an algebraic equation
  71. IV relationship for an inductor or capacitor is _____ in the time domain
    an ordinary differential equation
  72. Impedance of a resistor, capacitor, and inductor are derived from the ____ of each.
    current voltage relationship
  73. Definition of impedance is Z(s)=
    V(s)/I(s)
  74. The impedance in Ohms of a capacitor is _____ Ohms.
    1/(sC) = (1/C)/s
  75. The impedance in Ohms of an inductor is _____ Ohms.
    sL
  76. The impedance in Ohms of a resistor is _____ Ohms.
    R
  77. complex number with Ohms units is called
    impedance
  78. (A angle(B)) = A*exp(j*B)
    true because A*exp(j*B) is mathematically rigorous
  79. The complex number (A angle(B)) represents the sinusoid
    A*sin(wt+B)
  80. A complex number that represents a sinusoid is called a
    phasor
  81. Y=1/Z and Z=1/Y, therefore R=1/G and G=1/R
    false
  82. The relationship between Z and Y is
    inverse
  83. In Y = G + jB, Y is ____; G is ____; B is ____, all in units of Siemens.
    adimttance, conductance, susceptance
  84. In Z = R + jX, Z is ____; R is ____; X is _____, all in units of Ohms.
    impedance, resistance, reactance
  85. A*(1 at -180 deg) =
    -A
  86. A*(1 at 180 deg)*(-1) =
    A
  87. A*(-1)*(-1) =
    A
  88. (-1 at 0 degrees) is a complex number equal to
    -1
  89. 1 at -180 degrees) is a complex number equal to
    -1
  90. (1 at 180 degrees) is a complex number equal to
    -1
  91. V1=(10 at -20 degrees) volts and V2=(50 at -60 degrees) volts. V1 ____ V2 by ____.
    leads, 40 degrees
  92. V1=(10 at 20 degrees) volts and V2=(50 at 60 degrees) volts. V1 ____ V2 by ____.
    lags, 40 degrees
  93. Steady state AC circuit analysis uses _____ techniques as for DC circuits.
    THE SAME
  94. jw-domain impedance in Ohms of an inductor has an angle of
    90 degrees
  95. jw-domain impedance in Ohms of a capacitor has an angle of
    -90 degrees
  96. jw-domain impedance in Ohms of a resistor has an angle of
    0
  97. A phasor is a complex number representing a
    sinusoidal voltage or current
  98. After 1 second, V(t)=-12exp(-4t)+13.4sin(2t+1.107) will be
    sinusoidal
  99. The transient in V(t)=-12exp(-4t)+13.4sin(2t+1.107) will be 98.2% complete at t=_____ second(s).
    1
  100. e steady state part of V(t)=-12exp(-4t)+13.4sin(2t+1.107) is
    13.4sin(2t+1.107)
  101. The transient part of V(t)=-12exp(-4t)+13.4sin(2t+1.107) is
    -12exp(-4t)
  102. V(t)=-12exp(-4t)+13.4sin(2t+1.107) is the voltage across the inductor in an RL circuit containing switch and 30sin(2t) voltage source in H342540 video
    true
  103. V(t)=-12exp(-4t)+13.4sin(2t+1.107) is the voltage across the inductor in an RL circuit containing switch and 30sin(2t) voltage source in H342540 video
    Kirchhoff's voltage law
  104. In V=(10 at 20 degrees) volts, is the phasor representation of
    v(t)=10*sin(w*t+20deg) volts
  105. In I=(10 at 20 degrees) amps, is the phasor representation of
    i(t)=10*sin(w*t+20deg) amps
  106. In Z = 30 - j40, the impedance angle is _____ degrees
     -53.13
  107. In Z = 30 + j40, the impedance angle is _____ degrees
    53.13
  108. In Z = 30 - j40, the impedance magnitude is ____ Ohms
    50
  109. In Z = 30 + j40, the impedance magnitude is ____ Ohms
    50
  110. In Z = 30 - j40, 40 Ohms is ______ reactance of 40 Ohms
    capacitor
  111. In Z = 30 + j40, 40 Ohms is ______ reactance of 40 Ohms
    inductor
  112. In Z = R + jX, X in Ohms is
    reactance
  113. In Z = R + jX, Z in Ohms is
    impedance
  114. In Z = R + jX, R in Ohms is
    resistance
  115. Square root of the average of a function squared is the same as RMS.
    true
  116. In S = 3 + j4, apparent power=_____, power=_____, and reactive power=_____.
    5 VA, 3 Watts, 4 VARs
  117. V*conj(V)/(2*conj(Z)) sto-> apvz(V,Z) creates a TI-89 function for complex power in terms of phasor voltage and jw-domain impedance.
    true, if the "*" means multiply
  118. I*conj(I)*Z/2 sto-> apiz(I,Z) creates a TI-89 function for complex power in terms of phasor current and jw-domain impedance.
    true, if the "*" means multiply
  119. . V*conj(I)/2 sto-> apiv(I,V) creates a TI-89 function for complex power in terms of phasor current and voltage
    true, if the "*" means multiply
  120. The "2" in S=VI^*/2 occurs when the phasor voltage or current amplitude is
    peak value
  121. If phasor voltage or current were defined using the RMS value instead of the peak value, then complex power would be
    S=VI^*
  122. S = V multiplied by I^* divided by 2 (S=VI^*/2) is analogous to the DC power formula (P=IV).
    true, when the "^*" means complex conjugate
  123. If A is a phasor, then A^* is complex conjugate of A
    true
  124. Complex conjugate of A+jB is
    A-jB
  125. Unity power factor (PF=1) is desirable because
    current is minimized
  126. Unity power factor (PF=1) occurs when
    Q=0
  127. In the power triange for S = P + jQ, _____ is the power factor (PF).
    cos(theta)
  128. . In the power triangle for S = P + jQ,
    • sin(theta) = |Q|/|S|
    • cos(thata) = P/|S|
    • tan(theta) = |Q|/P
    • all of these
  129. An resistor exchanges power in an AC circuit by absorbing power from the circuit and returning that power to the circuit every cycle.
    false
  130. An inductor exchanges power in an AC circuit by absorbing power from the circuit and returning that power to the circuit every cycle.
    true
  131. A capacitor exchanges power in an AC circuit by absorbing power from the circuit and returning that power to the circuit every cycle.
    true
  132. In complex power S = P + jQ, Q is power in VARS that is
    exchanged
  133. In complex power S = P + jQ, P is power in watts that is _______.
    dissipated or supplied
  134. Complex power is S = P + jQ, and Q is NEGATIVE, then Q is
    capacitive
  135. Complex power is S = P + jQ, and Q is POSITIVE, then Q is
    inductive
  136. The mathematical expression for complex power is S = P +- jQ where S is ____ and "+-" means plus or minus.
    apparent power in volt-amps (VA)
  137. The mathematical expression for complex power is S = P +- jQ where Q is ____ and "+-" means plus or minus.
    reactive power in VARS
  138. The mathematical expression for complex power is S = P +- jQ where P is ____ and "+-" means plus or minus.
    power in watts
  139. Complex power has units of
    • watts
    • all of these
    • volts-amps-reactive (VARS)
    • volt-amps
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lacythecoolest
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Card Set
ENT 342 exam II
Description
ENT 342 exam II preclass quiz ?'s
Updated