61.
The Lagrangian of a particle moving in a plane under the influence of a central potential is given by \[L = \frac{1}{2}m\left( {{{\dot r}^2} + {r^2}{{\dot \theta }^2}} \right) - V\left( r \right).\]      The generalized momenta corresponding to r and θ are given by

62.
The eigen values of the matrix \[\left[ {\begin{array}{*{20}{c}} {\cos \theta }&{ - \sin \theta } \\ {\sin \theta }&{\cos \theta } \end{array}} \right]\]   are

65.
The value of \[\oint\limits_C {\frac{{{e^{2z}}}}{{{{\left( {z + 1} \right)}^4}}}dz,} \]   where C is a circle defined by |z| = 3, is

66.
Sij and Aij represent a symmetric and an anti-symmetric real-valued tensor respectively in three-dimension. The number of independent components of Sij and Aij

68.
The curl of the vector \[\overrightarrow {\bf{A}} = z{\bf{\hat i}} + x{\bf{\hat j}} + y{\bf{\hat k}}\]    is given by

69.
The Fourier transform F(k) of a function f(x) is defined as $$F\left( k \right)\int_{ - \infty }^\infty {dxf\left( x \right)\exp \left( {ikx} \right).} $$     Then F(k) for f(x) = exp(-x2) is $$\left[ {{\text{Given: }}\int_{ - \infty }^\infty {\exp \left( { - {x^2}} \right)dx = \sqrt \pi } } \right]$$

70.
Two matrices A and B are said to be similar, if B = P-1 AP for some invertible matrix P. Which of the following statements is not true?