If $\overline{a}=\frac{1}{\sqrt{10}}(3 \hat{i}+\hat{k})$ and $\overline{b}=\frac{1}{7}(2 \hat{i}+3 \hat{j}-6 \hat{k})$,then the value of $(2 \overline{a}-\overline{b}) \cdot [(\overline{a} \times \overline{b}) \times (\overline{a}+2 \overline{b})]$ is

Consider the circle $x^2+y^2-4x-2y+c=0$ whose centre is $A(2,1)$. If the point $P(10,7)$ is such that the line segment $PA$ meets the circle at $Q$ with $PQ=5$,then $c$ is equal to

The catalyst used for the polymerization of olefins is....

The transition from the state $n=3$ to $n=1$ in a hydrogen-like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition from:

If $y=a \cos (\log x)+b \sin (\log x)$,where $a, b$ are parameters,then $x^2 y^{\prime \prime}+x y^{\prime}$ is equal to

$A$ force $F = -K(y\hat{i} + x\hat{j})$ (where $K$ is a positive constant) acts on a particle moving in the $xy$-plane. Starting from the origin,the particle is taken along the positive $x$-axis to the point $(a, 0)$ and then parallel to the $y$-axis to the point $(a, a)$. The total work done by the force $F$ on the particle is: