51.
For a physical system, two observables O1 and O2 are known to be compatible. Choose the correct implication from amongst those given below.

52.
A vector $$\overrightarrow A = \left( {5x + 2y} \right)\hat i + \left( {3y - z} \right)\hat j + \left( {2x - az} \right)\hat k$$        is solenoidal, if the constant a has a value

53.
The Fourier transform of the function f(x) is $$F\left( k \right) = \int {{e^{ikx}}f\left( x \right)dx.} $$     The Fourier transform of $$\frac{{df\left( x \right)}}{{dx}}$$  is

54.
The solution of the differential equation $$\left( {1 + x} \right)\frac{{{d^2}y\left( x \right)}}{{d{x^2}}} + x\frac{{dy\left( x \right)}}{{dx}} - y\left( x \right) = 0$$       is
where A and B are constants

55.
A 3 × 3 matrix has eigen values 0, 2 + i and 2 - i. Which one of the following statement is correct?

57.
Which one of the following curves gives the solution of the differential equation $${k_1}\frac{{dx}}{{dt}} + {k_2}x = {k_3},$$    where k1, k2 and k3 are positive constant with initial conditions x = 0 and t = 0?

58.
The eigen values and eigen vectors of the matrix \[\left[ {\begin{array}{*{20}{c}} 5&4 \\ 1&2 \end{array}} \right]\]  are

59.
If a force \[\overrightarrow {\mathbf{F}} \] is derivable from a potential function V(r), where r is the distance from the origin of the coordinate system, it follows that