Page 73 - Engineering Mathematics Workbook_Final
P. 73

Vector Calculus


            127. The value of    Fdr where                              (d)  R R =   d R
                                                                               
                              C
                                                                                       dt
                   =
                              +
                 F xyi +  yzj zxk  and C is the curve
                                                                                            [GATE-2005 ; (IN)]
                      +
                  =
                         2
                              3
                            +
                r ti t j t k from t =  to  t =    1is ____        131.   The area of a triangle formed by the tips
                                          0
                    28                       27                          of vectors a , b  and c  is
                (a)                      (b)
                    27                       28
                                                                             1 (     ) (       )
                                                                                  −
                                                                                            −
                    29                                                   (a)    a b      a c
                (c)                      (d)1                                2
                    28
                                                                                      ) (
                                                                                                )
                                                                             1
                                                                                            −
                                                                                  −
            128. Let  p = 3i + 2 j k and  q i = + 2j + 3k be             (b)   ( a b     a c
                                 +
                                                                             2
                                                   +
                                              +
                vectors in  R .Suppose  V =  ai bj ck is  a
                             3
                                                                             1
                                                                                 
                                                                                     
                                                 =
                unit  vector  such  that  v .p =  0 v .q The             (c)   2  a b c
                value of  a b c =   _____                                    1
                           + +
                                                                                  
                                                                         (d)   ( a b   )  c
                (a) 6                    (b) 3                               2
                (c) 1                    (d) 0                                                [GATE-2007-ME]
            129.   If  P,  Q  and  R  are  three  points  having
                   coordinates (3, -2, -1), (1, 3, 4), (2, 1, -2)   132.   If a  and b  are two arbitrary vectors
                   in XYZ space (o being the origin of the               with magnitudes a and b, respectively,
                                                                                2
                   coordinate system) then distance of point              a b  will be equal to
                                                                            
                   P from plane OQR is
                   (a) 3                 (b) 7                                2 2   (      ) 2
                                                                                       
                                                                         (a) a b −   a b
                   (c) 5                 (d) 9
                                                                                    
                                                                                −
                                                                         (b) ab a b
                                             [GATE-2003]
                                                                                       
                              R
            130.   If a vector  ( ) t  has a constant                    (c) a b + 2 2  ( a b ) 2
                   magnitude than
                                                                                +
                                                                         (d) ab a b              [GATE-2011-CE]
                           d R
                   (a)  R      =  0
                            dt                                    133.   If A (0, 4, 3), B (0, 0, 0) and C (3, 0, 4)
                                                                         are three points defined in x, y, z
                           d R
                   (b)  R      =  0                                     coordinate system, then which one of the
                            dt                                           following vectors is perpendicular to

                                                                         both the vectors  AB  and  BC
                             d R
                   (c)  R R      =  0
                              dt


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