Page 57 - Engineering Mathematics Workbook_Final
P. 57

Vector Calculus

                   (c) -1 and 3          (d) 2 and 2                     along the path  : c x t ,  y t =  3 ,
                                                                                            =
                                                                                               2
                                             2
                                                  2
            12.    Let C be the circle (x −  ) 1 +  y = 1,               0 t     1 is _____________
                   oriented counter clockwise. Then, the                                        [JAM MA 2016]
                   value of the line integral

                       C   −  4  xy dx +  3  x dy  is            16.    Let C be the boundary of the region
                                       4
                                                                                           2
                          3                                              enclosed by  y x=  ,  y =  x +  2  and
                                                                         x = 0. Then the value of the line
                   (a) 6        (b) 8
                                                                                                       3
                                                                         integral   C   ( xy −  y 2 ) dx −  x dy ,
                   (c) 12               (d) 14                         where C is traversed in the counter

                                          [JAM MA 2019]                  clockwise direction, is ____________
                       ur                                                                       [JAM MA 2016]
                                               $
                                                     $
                                             2
                                 ) 2y i +
                       F x
            13.    Let  ( , , y z =     $   x j +  xyk
                   and let C be the curve of intersection of      17.    Let T be the smallest positive real
                   the plane  x + + =    1 and cylinder                  number such that the tangent to the helix
                                 y
                                     z
                                                                                            t
                                                                                               $
                   x +  2  y 2  1 =  . Then the value of                 cost i +  $  sint j +  $  2  k  at t = T is
                       C   ur   r                                      orthogonal to the tangent at t= =0. Then
                         F dr  is
                                                                                            ur
                                                                                                        $
                                                                         the line integral of  F =  x i −  $  y j  along
                                             3                          the section of the helix from t = 0 to t =
                   (a)                  (b)                             T is ________
                                              2
                                                                                                [JAM MA 2017]
                   (c) 2        (d) 3                                      ur            $     $
                                                                                     )
                                                                                             +
                                                                             F
                                          [JAM MA 2019]           18.    Let  ( , x y = − y i x j  and let C be
            14.    Evaluate   C   yzdx +  zxdy +  xydz                  the ellipse   x 2  +  y 2  =  1 oriented
                                                                                    16
                                                                                          9
                                                =
                   where C is the are of curve  x b cost ,               counter clockwise. Then the value of
                                    at                                        ur     r
                                                                                 
                     =
                    y b  sint ,  z =    from the point                      C   F dr  (round off to 2 decimal
                                    2
                                 0
                   intersects  z =  to the point it intersects           places) is ________
                     =
                   z a.                                                                         [JAM MA 2019]
                       ur
                                $
                                             $
            15.    Let  F =   x i +  ( x +  y 3 ) j  be a vector   19.   Let C be the boundary of region    x   1 y  2 
                                                                                    )
                                                                         R =
                                                                                                  y 
                                                                                           : 1
                                                                                            −
                                                                                                                  −
                                                                                                      1,0  
                                                                               (  ,x y 
                                                                                          2
                                                                                        R
                                    )
                                               0
                   field for all ( ,x y  with x  and                     oriented in the counter-clockwise
                   r                                                     direction. Then the value of
                               $
                   r =  x i +  $  y j . Then the value of the line         ydx +  2xdy  is
                                     r
                               ur
                             C                                          C
                   integral    F dr  from (0, 0) to (1, 1)

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