Evaluate the surface integral ∫∫ (3x i + 2y j). dS, where S is the sphere given by x 2 +
y 2 + z 2 = 9.
a) 120π
b) 180π
c) 240π
d) 300π

1 Answer

Answer :

b) 180π

Related questions

Description : Evaluate Gauss law for D = 5r 2 /4 i in spherical coordinates with r = 4m and θ = π/2 as volume integral. a) 600 b) 588.9 c) 577.8 d) 599.7

Last Answer : b) 588.9

Description : Find current density J when B = 50 x 10-6 units and area dS is 4 units. a) 9.94 b) 8.97 c) 7.92 d) 10.21

Last Answer : b) 8.97

Description : The current element of the magnetic vector potential for a surface current will be a) J dS b) I dL c) K dS d) J dV

Last Answer : c) K dS

Description : Find the magnetic field intensity when the magnetic vector potential x i + 2y j + 3z k. a) 6 b) -6 c) 0 d) 1

Last Answer : b) -6

Description : Find the flux density B when the potential is given by x i + y j + z k in air. a) 12π x 10 -7 b) -12π x 10 -7 c) 6π x 10 -7 d) -6π x 10 -7

Last Answer : b) -12π x 10 -7

Description : Find the value of divergence theorem for the field D = 2xy i + x 2 j for the rectangular parallelepiped given by x = 0 and 1, y = 0 and 2, z = 0 and 3. a) 10 b) 12 c) 14 d) 16

Last Answer : b) 12

Description : Find the value of divergence theorem for the field D = 2xy i + x 2 j for the rectangular parallelepiped given by x = 0 and 1, y = 0 and 2, z = 0 and 3. a) 10 b) 12 c) 14 d) 16

Last Answer : b) 12

Description : Find the value of divergence theorem for A = xy 2 i + y 3 j + y 2 z k for a cuboid given by 0

Last Answer : c) 5/3

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 : 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 : Which of the following theorem convert line integral to surface integral? a) Gauss divergence and Stoke’s theorem b) Stoke’s theorem only c) Green’ s theorem only d) Stoke’s and Green’s theorem

Last Answer : d) Stoke’s and Green’s theorem

Description : What is the angle between the lines whose equations are: 3x + y – 7 = 0 and x + 2y + 9 = 0. -Maths 9th

Last Answer : (c) (8, 6)Let AB be the given line 4x + 3y = 25 Let O′(a, b) be the image of O in the given line AB. Let O O′ cut AB in point P. Also OP ⊥ AB and P is the mid-point of OO′. ∴ Co-ordinates of P are \(\bigg( ... 4 imes6}{3}\) = 8∴ The image of the point O(0, 0) in the line 4x + 3y - 25 = 0 is (8, 6).

Description : Find the current density on the conductor surface when a magnetic field H = 3cos x i + zcos x j A/m, for z>0 and zero, otherwise is applied to a perfectly conducting surface in xy plane. a) cos x i b) –cos x i c) cos x j d) –cos x j

Last Answer : b) –cos x i

Description : Find the magnetic flux density of the material with magnetic vector potential A = y i + z j + x k. a) i + j + k b) –i – j – k c) –i-j d) –i-k

Last Answer : b) –i – j – k

Description : Find the value of Stoke’s theorem for A = x i + y j + z k. The state of the function will be a) Solenoidal b) Divergent c) Rotational d) Curl free

Last Answer : d) Curl free

Description : Find the value of Stoke’s theorem for y i + z j + x k. a) i + j b) j + k c) i + j + k d) –i – j – k

Last Answer : d) –i – j – k

Description : If D = 2xy i + 3yz j + 4xz k, how much flux passes through x = 3 plane for which - 1

Last Answer : c) 36

Description : Find the gradient of t = x 2 y+ e z at the point p(1,5,-2) a) i + 10j + 0.135k b) 10i + j + 0.135k c) i + 0.135j + 10k d) 10i + 0.135j + k

Last Answer : b) 10i + j + 0.135k

Description : Compute the Gauss law for D = 10ρ 3 /4 i, in cylindrical coordinates with ρ = 4m, z = 0 and z = 5, hence find charge using volume integral. a) 6100 π b) 6200 π c) 6300 π d) 6400 π View Answe

Last Answer : d) 6400 π

Description : Calculate the charge density for the current density given 20sin x i + ycos z j at the origin. a) 20t b) 21t c) 19t d) -20t

Last Answer : b) 21t

Description : The spherical equivalent of the vector B = yi + (x + z)j located at (-2,6,3) is given by a) (7,64.62,71.57) b) (7,-64.62,-71.57) c) (7,-64.62,71.57) d) (7,64.62,-71.57)

Last Answer : d) (7,64.62,-71.57)

Description : The surface integral of which parameter is zero? a) E b) D c) B d) H

Last Answer : c) B

Description : Which equation will hold good for a magnetic material? a) Line integral of H is zero b) Surface integral of H is zero c) Line integral of B is zero d) Surface integral of B is zero

Last Answer : d) Surface integral of B is zero

Description : For a solenoidal field, the surface integral of D will be, a) 0 b) 1 c) 2 d) 3

Last Answer : a) 0

Description : In the conversion of line integral of H into surface integral, which theorem is used? a) Green theorem b) Gauss theorem c) Stokes theore d) It cannot be converted

Last Answer : c) Stokes theorem

Description : The Gauss divergence theorem converts a) line to surface integral b) line to volume integral c) surface to line integral d) surface to volume integral

Last Answer : d) surface to volume integral

Description : The divergence theorem converts a) Line to surface integral b) Surface to volume integral c) Volume to line integral d) Surface to line integral

Last Answer : b) Surface to volume integral

Description : Surface integral is used to compute a) Surface b) Area c) Volume d) density

Last Answer : b) Area

Description : Gauss law for electric field uses surface integral. State True/False a) True b) False

Last Answer : a) True

Description : Find the curl of the vector A = yz i + 4xy j + y k a) xi + j + (4y – z)k b) xi + yj + (z – 4y)k c) i + j + (4y – z)k d) i + yj + (4y – z)k

Last Answer : d) i + yj + (4y – z)k

Description : Find the electric field of a potential function given by 20 log x + y at the point (1,1,0). a) -20 i – j b) -i -20 j c) i + j d) (i + j)/20

Last Answer : a) -20 i – j

Description : Given D = e -x sin y i – e -x cos y j Find divergence of D. a) 3 b) 2 c) 1 d) 0

Last Answer : d) 0

Description : The integral form of potential and field relation is given by line integral. State True/False a) True b) False

Last Answer : a) True

Description : An electric field is given as E = 6y 2 z i + 12xyz j + 6xy 2 k. An incremental path is given by dl = -3 i + 5 j – 2 k mm. The work done in moving a 2mC charge along the path if the location of the path is at p(0,2,5) is (in Joule) a) 0.64 b) 0.72 c) 0.78 d) 0.80

Last Answer : b) 0.72

Description : The Gaussian surface for a point charge will be a) Cube b) Cylinder c) Sphere d) Cuboid

Last Answer : c) Sphere

Description : The Gaussian surface for a line charge will be a) Sphere b) Cylinder c) Cube d) Cuboid

Last Answer : b) Cylinder

Description : The divergence theorem for a surface consisting of a sphere is computed in which coordinate system? a) Cartesian b) Cylindrical c) Spherical d) Depends on the function

Last Answer : d) Depends on the function

Description : Draw a graph of the equation x + Y = 5 & 3x - 2y =0 on the same graph paper. Find the coordinates of the point whose two lines intersect. -Maths 9th

Last Answer : This answer was deleted by our moderators...

Description : Draw a graph of the equation x+ y=5 & 3x -2y=0 in the same graph paper find the coordinates of the point whose two two lines intersect. -Maths 9th

Last Answer : From x + y = 5, If x = 0 0 + y = 5 y = 5 Therefore (0,5) If x = 1 1 + y = 5 y =5 - 1 y = 4 Therefore (1,4) Draw a graph for this And From 3x - 2y = 0 If x = 0 3 (0) - 2y = 0 0 - ... 2y = 0 -2y = -6 y = -6/-2 y = 3 Therefore (2,3) Draw a graph for these points And the point of intersection is (2,3)

Description : if x:y=5:7 then find `(3x+4y):(x+2y)` .

Last Answer : if x:y=5:7 then find `(3x+4y):(x+2y)` .

Description : If a + b = 1 ,and the ordered pair (a, b) satisfies the equation 2x + y = , then it also satisfies (a) 2x + y (b) 3x + 4y = 3 (c) x + 2y = (d) 2x + 4y =

Last Answer : (c) x + 2y =

Description : If (x, y) is a solution of the following pair of linear equations in two variables, then the value of expression (√ is: x + 2y = 4 and 3x - y = 5 (a) 2 (b) 3 (c) 4 (d) √2

Last Answer : (a) 2

Description : The coordinates of the vertices of region bounded by lines 3x - y = 5; x+ 2y = 4 and Y-axis are: (a) A(2,0); B(5,0) and C(1,2) (b) A(2,0); B(-5,0) and C(1,2) (c) A(0,2); B(0,-5) and C(2,1) (d) A(0,2); B(0,5) and C(2,1)

Last Answer : (c) A(0,2); B(0,-5) and C(2,1)

Description : A pair of linear equations which has a unique solution x = 2, y = -3 is (a) x + y = -1 ; 2x – 3y = -5 (b) 2x + 5y = -11 ; 4x + 10y = -22(c) 2x – y = 1 ; 3x + 2y = 0 (d) x – 4y – 14 = 0 ;5x – y – 13 = 0

Last Answer : (d) x – 4y – 14 = 0 ;5x – y – 13 = 0

Description : Find the charge density when the electric flux density is given by 2x i + 3y j + 4z k. a) 10 b) 9 c) 24 d) 0

Last Answer : b) 9

Description : Transform the vector B=yi+(x+z)j located at point (-2,6,3) into cylindrical coordinates. a) (6.325,-71.57,3) b) (6.325,71.57,3) c) (6.325,73.57,3) d) (6.325,-73.57,3)

Last Answer : a) (6.325,-71.57,3)

Description : Given the vector potential is 16 – 12sin y j. Find the field intensity at the origin. a) 28 b) 16 c) 12 d) 4

Last Answer : c) 12

Description : Evaluate Gauss law for D = 5r 2 /4 i in spherical coordinates with r = 4m and θ = π/2. a) 600 b) 599.8 c) 588.9 d) 577.8

Last Answer : c) 588.9

Description : If the radius of a sphere is 1/(4π)m and the electric flux density is 16π units, the total flux is given by, a) 2 b) 3 c) 4 d) 5

Last Answer : c) 4