Page 81 - Engineering Mathematics Workbook_Final
P. 81

Vector Calculus
                                  ydx zdy +
                                        +
            182.   The value of                  xdz                             y        $ j +      z        k
                                                                                                              $
                                 C                                       ( x +  2  y +  2  z 2 ) 3/ 2  ( x +  2  y +  2  z 2 ) 3/ 2
                   where C is the intersection of
                     2
                               2
                                     2
                   x +   y +  z =  a  and  x z a .                              $ $ $
                          2
                                             +
                                                 =
                                                                         where  i ,  j , k  are unit vectors along
            183.   The value of                                          the axes of a right-handed rectangular /
                                                  )
                       ( (   2x −  ) y i −  yz j −  y zk dr .           Cartesian coordinate system. The surface
                                              2
                                       2
                                                                                      u r
                                                                                                       u r
                                                                                           u r
                    C                                                    integral     f   dS  (where  dS  is an
                   Where C is the boundary of upper half of              elemental surface area vector) evaluated
                   the surface of the sphere                             over the inner and outer surfaces of a
                                2
                          2
                     2
                    x +  y +  z =  1 above xy plane is                   spherical shell formed by two concentric
                                                                         spheres with origin as the center, and
                                            −
                   (a)                  (b)                            internal and external radii of 1 and 2,
                                                                         respectively, is
                   (c) 2                (d) 0
                                                                         (a) 4                (b) 0
            184.   Given vector
                                              )
                        1                                                (c) 2                (d) 8
                                      $
                                            $
                              3 $
                                                    $
                                    3
                                           3
                   u =   ( − y i +  x j +  z k  and n  as
                        3                                                                [GATE-20-ME-SET 1]
                   the unit normal vector to the surface of
                   the hemisphere                                 186.   The value of
                                                                                                )
                   ( x +  y +  z =  1;z   0 ) , the value of               (   4xi −  2y j +  z k   nds  where S
                                                                                                    $
                                                                                      2
                                                                                             2
                           2
                      2
                                 2
                                                                          S
                                     )
                   integral  (     u   n dS  evaluated               is bounded by  x +  2  y =  2  4 ,  z =  and
                                                                                                          0
                   on the curved surface of the hemisphere               z =  2 is
                   S is
                                                                         (a) 16               (b) 48
                                           
                   (a) −                 (b)                             (c) 32               (d) 84
                         2                   3
                                                                                              $
                                                                 187.  The value of    F   nds  where S is the
                   (c)                   (d)                                          S
                       2                                                 surface of the sphere  x +  y +  z =  4
                                                                                                          2
                                                                                                     2
                                                                                               2
                                                                                $
                                   [GATE-19-ME-SET 2]                    where n  is the unit normal and
            185.   A vector field is defined as                          F =  xi +  y j +  zk  is ________
                   ur                  x
                    f  ( , ,x y z =  )      3/ 2  $ i +                  (a) 32               (b) 16
                               ( x +  2  y +  2  z 2 )
                                                                         (c) 8                (d) 64





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