Page 58 - Engineering Mathematics Workbook_Final
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Vector Calculus

                        4 −            2 −                                   5
                   (a)           (b)                                     (a)                   (b) 3
                       3              3                                      2


                       2                     4                           (c) 4                 (d) 5
                   (c)                   (d)
                       3                     3                                                  [JAM MA 2018]
                                                                                                       ur     u r
                                          [JAM MA 2014]
                                                                  23.    The value of the integral     F   dS ,
            20.    The value of the integral                                    ur                 S
                                                                                        $
                                                                                                    $
                                                                                               $
                      (x +   ) y dx x dy , where C is the               where  F =  3x i +  2y j +  zk  and S is
                                  +
                                      2
                    C                                                    the closed surface given by the planes
                   triangle with vertices (0, 0), (2, 0) and             x = 0, x =
                                                                                                          0
                                                                                            0
                                                                                                   2
                   (2, 4) in the anticlockwise direction is                         1,  y = ,  y = , z =  and
                                                                         z =
                   (a) 5/3               (b) 10/3                            3 is
                   (c) 20/3              (d) 40/3                        (a) 6                 (b) 18
                                           [JAM GP 2010]                 (c) 24                (d) 36

                                               $
                                                     $
                                       ur     x i −  y j                                        [JAM GP 2009]
            21.    For a > 0, b > 0, let  F =
                                            b x +  a y  2                            ur    $     $    2  $
                                                     2
                                             2 2
                                                                                             −
                                                                                                  +
                   be a planar vector field.                      24.    The flux of  F =  y i x j z k  along
                                                                         the outward normal, across the surface of
                   Let                                                   the solid
                   C =   (   , x  ) y  R x +  y = a +  b 2 
                                             2
                                                  2
                                    2
                                       2
                                                                          )
                                                                                                             −
                                                                                    x
                                                                                                                2
                                                                                                       z
                                                                    x
                   be the circle oriented anti-clockwise.          ( , , y z  R 3  0   1, 0   y  1, 0    2 x −  y 2 
                              ur
                                    r
                            C   F dr =                                  is equal to
                   Then
                       2                                                    2                    5
                   (a)                   (b) 2                          (a)                   (b)
                       ab                                                    3                    3
                   (c) 2 ab             (d) 0                           (c)  8                (d)  4
                                                                             3                    3
            22.    If
                   ur
                                                         $
                                         $
                           ) (3x −
                   F  ( , x y =      8y ) i + (4y − 6xy ) j                                     [JAM MA 2017]
                                                   r
                   for ( ,x y ) R  2 , then     ur  dr ,        25.    Let S be the closed surface forming the
                                            F 
                                          C                              boundary of the region V bounded by
                   where C is the boundary of the triangular               2     2
                                                                               y =
                                                                                                   6
                                                                                            0
                                                   0
                   region bounded by the lines x = ,                     x +  ur    3, z = , z = . A vector
                    y =  0 and  x +  y =  1 oriented in the
                                                                         field F  is defined over V with
                   anti-clockwise direction, is                               ur
                                                                                      +
                                                                            F = 2y z +    1. Then the value of

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