Which of the following ions will exhibit colour in aqueous solutions?

The equation of the circle which passes through the origin and cuts orthogonally each of the circles $x^2+y^2-6x+8=0$ and $x^2+y^2-2x-2y-7=0$ is

The figure given below shows a small part of human lung where exchange of gases takes place. In which one of the options given below,the one part $A, B, C$ or $D$ is correctly identified along with its function?

What is obtained by the electrolysis of carnallite?

The logical statement $[\sim(\sim p \vee q) \vee (p \wedge r)] \wedge (\sim q \wedge r)$ is equivalent to

Let $l_1$ and $l_2$ be two lines intersecting at $P$. If $A_1, B_1, C_1$ are points on $l_1$,and $A_2, B_2, C_2, D_2, E_2$ are points on $l_2$,and if none of these coincides with $P$,then the number of triangles formed by these eight points is: