For $x \in \mathbb{R}$,the least value of $\frac{x^2-6x+5}{x^2+2x+1}$ is

Which of the following is an amphoteric hydroxide?

Two coherent point sources $S_1$ and $S_2$ vibrating in phase emit light of wavelength $\lambda$. The separation between them is $2 \lambda$ as shown in the figure. The first bright fringe is formed at $P$ due to interference on a screen placed at a distance $D$ from $S_1$ $(D >> \lambda)$. Then the distance $OP$ is:

When substance $A$ reacts with water,it produces a combustible gas $B$ and a solution of substance $C$ in water. When another substance $D$ reacts with solution $C$,it produces the same gas $B$ even when reacting with dilute sulfuric acid at room temperature. $A$ imparts a golden yellow color to the non-luminous flame of a Bunsen burner. What are $A$,$B$,$C$,and $D$ respectively?

Total number of secondary amines (excluding stereoisomers) possible with the molecular formula $C_5H_{13}N$ is

Which of the following series of transition metal ions all have a $3d^2$ electronic configuration?