Page 64 - Engineering Mathematics Workbook_Final
P. 64

Vector Calculus

                       1                                                 (d) a +  b +  c =   0          [JAM 2012]
                                                                                    2
                                                                                         2
                                                                              2
                   (c)                   (d) 1
                       2
                                                                                                   3
                                                                  60.    If C is a smooth curve in  R  from (0, 0,
                                              [JAM 2010]                             )
                                                                         0) to (2,1, 1 − , then the value of
                                                                                               )
                                          $
                               $
                                    $
                                      +
                                                                                   )
                                                                                                          )
                                                                                           +
                                                                                                       +
                                                                                              2
                                                                                +
            57.    Let  F = ayi +  z j xk  and C is the                    (2xy z dx +  ( z x dy +  (x y dz  is
                                                                          C
                   positive oriented closed curve given by
                                                                         __________
                   x +  2  y 2  1 =  , z = . If    F   dr                 −
                                    0
                                                     =
                                          C                              (a)  1                (b) 0
                   then the value of a is _________                      (c) 1                 (d) 2
                       −
                   (a)  1                (b) 0                                                      [JAM 2012]
                       1                                          61.    The value of n for which the divergence
                   (c)                   (d) 1
                       2                                                                      r
                                                                         of the function  F =  n  , where
                                              [JAM 2011]                                     r
                                                                                      +
                                                                                +
                                                                         r xi y j zk ,  r       0  vanishes is
                                                                           =
            58.    Consider the vector field
                                         $
                                                     $
                                      $
                   F =  (ax + +     ) a i + − (x +  ) y k ,              _________
                                          j
                               y
                                                                                                  −
                   where a is constant.                                      (a) 1             (b)  1
                   If  F   curlF =  0 then the value of a is
                   ___________                                           (c) 3                 (d)  3 −
                                                                                                    [JAM 2013]
                   (a)  1−               (b) 0
                                                                                                2
                                             3                    62.    Let  be the triangle  R  with vertices
                   (c) 1                 (d)                             (0, 0) (1, 0) and (0, 1) and let
                                             2
                                                                                 )
                                                                                                4
                                                                         F  ( , x y = − xyi +  y +  1 j . The line
                                              [JAM 2011]
                                                                                      
                                                                         integral    F dr  taking anticlock
                                  $
                                            $
                                       $
                                         +
            59.    For C > 0, if ai +  b j ck  is the unit                       
                                    (       )                            wise orientation of  
                   normal vector at  1,1, 2  to the cone
                                                                              1 −
                   z =   x +  2  y , then ___________                    (a)   6               (b) 0
                                2
                                                                             1
                                   2
                             2
                        2
                   (a) a +  b −  c =  0                                  (c)   6               (d) 6
                                                                                                     [IISC 2006]
                                    2
                               2
                   (b)  a−  2  + b + c = 0
                                   2
                             2
                        2
                   (c) a −  b +  c =  0

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