Description : The skin depth of the wave having a frequency of 3MHz and a velocity of 12 m/s is a) 2 b) 3 c) 4 d) 6
Last Answer : c) 4
Description : Calculate the skin depth of a conductor, having a conductivity of 200 units. The wave frequency is 10 GHz in air. a) 355.8 b) 3.558 c) 35.58 d) 0.3558
Last Answer : a) 355.8
Description : Colebrook equation for friction factor in turbulent flow is given by, f -0.5 = -4 loge [(ε/D) + (1.26/NRe √F). It reduces to Nikuradse equation for a value of (ϵ/D) equal to (A) 0 (B) 1 (C) ∞ (D) 0.5
Last Answer : (B) 1
Description : The skin depth is used to find which parameter? a) DC resistance b) AC resistance c) Permittivity d) Potential
Last Answer : b) AC resistance
Description : The effective skin resistance of a material with conductivity 120 and skin depth of 2μm is a) 4.16 kilo ohm b) 4.16 mega ohm c) 41.6 kilo ohm d) 41.6 mega ohm
Last Answer : a) 4.16 kilo ohm
Description : The attenuation constant is 0.5 units. The skin depth will be a) 0.5 b) 0.25 c) 2 d) 4
Last Answer : c) 2
Description : The skin depth is calculated from the amplitude of the wave. State true/false a) True b) False
Last Answer : a) True
Description : The skin depth is measured in a) Meter b) Millimetre c) Centimetre d) Micrometer
Last Answer : d) Micrometer
Description : The skin depth of a wave with phase constant of 12 units inside a conductor is a) 12 b) 1/12 c) 24 d) 1/24
Last Answer : b) 1/12
Description : The skin depth of a conductor with attenuation constant of 7 neper/m is a) 14 b) 49 c) 7 d) 1/7
Last Answer : d) 1/7
Description : In conductors, which two parameters are same? a) Wavelength and phase constant b) Phase and attenuation constant c) Attenuation constant and skin depth d) Skin depth and wavelength
Last Answer : b) Phase and attenuation constant
Description : Skin depth phenomenon is found in which materials? a) Insulators b) Dielectrics c) Conductors d) Semiconductors
Last Answer : c) Conductors
Description : Calculate the phase constant of a wave with skin depth of 2.5 units. a) 5/2 b) 5 c) 2 d) 2/5
Last Answer : d) 2/5
Description : Calculate the skin depth of a material with attenuation constant of 2 units. a) 2 b) 1 c) 0.5 d) 4
Last Answer : c) 0.5
Description : The equation f -0.5 = 4.07 loge (NRe √f) -0.6 is called the __________. (A) Colebrook formula (B) Von-Karman equation (C) Fanning equation (D) None of these
Last Answer : (B) Von-Karman equation
Description : The equation relating friction factor to Reynold number, f -0.5 = 4 loge (NRe /√f) -0.4 , is called the __________ equation. (A) Nikuradse (B) Von-Karman
Last Answer : (B) Ergun's
Description : The integral form of potential and field relation is given by line integral. State True/False a) True b) False
Description : The relation between vector potential and field strength is given by a) Gradient b) Divergence c) Curl d) Del operator
Last Answer : a) Gradient
Description : The work-electric field relation is given by a) Volume integral b) Surface integral c) Line integral d) Relation impossible
Last Answer : c) Line integral
Description : For a function given by F = 4x i + 7y j +z k, the divergence theorem evaluates to which of the values given, if the surface considered is a cone of radius 1/2π m and height 4π 2 m. a) 1 b) 2 c) 3 d) 4
Last Answer : b) 2
Description : The relation between the speed of light, permeability and permittivity is a) C = 1/√(με) b) C = με c) C = μ/ε d) C = 1/με
Last Answer : a) C = 1/√(με)
Description : Find the correct relation between current density and magnetization. a) J = Grad(M) b) J = Div(M) c) J = Curl(M) d) M = Curl(J)
Last Answer : c) J = Curl(M)
Description : Choose the best relation. a) A = -Div(V) b) V = Curl(A) c) H = -Grad(V) d) V = Div(E)
Last Answer : c) H = -Grad(V)
Description : Which of the following relation will hold good? a) D = μ H b) B = ε E c) E = ε D d) B = μ H
Last Answer : d) B = μ H
Description : The relation between flux density and vector potential is a) B = Curl(A) b) A = Curl(B) c) B = Div(A) d) A = Div(B)
Last Answer : a) B = Curl(A)
Description : The electric flux density and electric field intensity have which of the following relation? a) Linear b) Nonlinear c) Inversely linear d) Inversely nonlinear
Last Answer : a) Linear
Description : From the formula F = qE, can prove that work done is a product of force and displacement. State True/False a) True b) False
Description : If a function is described by F = (3x + z, y 2 − sin x 2 z, xz + ye x5 ), then the divergence theorem value in the region 0
Last Answer : c) 39
Description : Calculate the Green’s value for the functions F = y 2 and G = x 2 for the region x = 1 and y = 2 from origin. a) 0 b) 2 c) -2 d) 1
Last Answer : c) -2
Description : Find the value of Green’s theorem for F = x 2 and G = y 2 is a) 0 b) 1 c) 2 d) 3
Last Answer : a) 0
Description : Find the curl of the vector and state its nature at (1,1,-0.2) F = 30 i + 2xy j + 5xz 2 k a) √4.01 b) √4.02 c) √4.03 d) √4.04
Last Answer : d) √4.04
Description : Determine the divergence of F = 30 i + 2xy j + 5xz 2 k at (1,1,-0.2) and state the nature of the field. a) 1, solenoidal b) 0, solenoidal c) 1, divergent d) 0, divergent
Last Answer : b) 0, solenoidal
Description : Find the divergence of the vector F= xe -x i + y j – xz k a) (1 – x)(1 + e -x ) b) (x – 1)(1 + e -x ) c) (1 – x)(1 – e) d) (x – 1)(1 – e)
Last Answer : a) (1 – x)(1 + e -x )
Description : he work done of vectors force F and distance d, separated by angle θ can be calculated using, a) Cross product b) Dot product c) Addition of two vectors d) Cannot be calculated
Last Answer : b) Dot product
Description : The skin effect is a phenomenon observed in a) Insulators b) Dielectrics c) Conductors d) Semiconductors
Description : The phase constant of a wave propagation with frequency of 35 radian/sec and time delay of 7.5 sec is a) 4.66 b) 262.5 c) 46.6 d) 26.25
Last Answer : b) 262.5
Description : The group delay of a wave with phase constant 2.5 units and frequency of 1.2 radian/sec is a) 3.7 b) 1.3 c) 3 d) 2.08
Last Answer : d) 2.08
Description : The frequency in rad/sec of a wave with velocity of that of light and phase constant of 20 units is (in GHz) a) 6 b) 60 c) 600 d) 0.6
Last Answer : a) 6
Description : Calculate the phase constant of a dielectric with frequency 6 x 10 6 in air. a) 2 b) 0.2 c) 0.02 d) 0.002
Last Answer : c) 0.02
Description : Calculate the attenuation constant of a conductor of conductivity 200 units, frequency 1M radian/s in air. a) 11.2 b) 1.12 c) 56.23 d) 5.62
Last Answer : a) 11.2
Description : In free space, the ratio of frequency to the velocity of light gives the phase constant. State True/False. a) True b) False
Description : Calculate the velocity of wave propagation in a conductor with frequency 5 x 10 8 rad/s and phase constant of 3 x 10 8 units. a) 3/5 b) 15 c) 5/3 d) 8
Last Answer : c) 5/3
Description : Calculate the velocity of a wave with frequency 2 x10 9 rad/s and phase constant of 4 x 10 8 units. a) 0.5 b) 5 c) 0.2 d) 2
Last Answer : b) 5
Description : Calculate the phase constant of a wave with frequency 12 rad/s and velocity 3×10 8 m/s(in 10 -8 order) a) 0.5 b) 72 c) 4 d) 3
Description : For a perfect dielectric, which parameter will be zero? a) Conductivity b) Frequency c) Permittivity d) Permeability
Last Answer : a) Conductivity
Description : Find the equation of displacement current density in frequency domain. a) Jd = jwεE b) Jd = jwεH c) Jd = wεE/j d) Jd = jεE/w
Last Answer : a) Jd = jwεE
Description : When the Maxwell equation is expressed in frequency domain, then which substitution is possible? a) d/dt = w/j b) d/dt = j/w c) d/dt = jw
Last Answer : c) d/dt = jw
Description : Calculate the Larmer angular frequency for a magnetic flux density of 12.34 x 10 -10 . a) 108.36 b) 810.63 c) 368.81 d) 183.36
Last Answer : a) 108.36
Description : Calculate the frequency at which the conduction and displacement currents become equal with unity conductivity in a material of permittivity 2. a) 18 GHz b) 9 GHz c) 36 GHz d) 24 GHz
Last Answer : b) 9 GHz
Description : Find the magnitude of the displacement current density in air at a frequency of 18GHz in frequency domain. Take electric field E as 4 units. a) 18 b) 72 c) 36 d) 4
Last Answer : d) 4