$300 \text{ g}$ of water at $25^{\circ} \text{C}$ is added to $100 \text{ g}$ of ice at $0^{\circ} \text{C}$. The final temperature of the mixture will be (in $^{\circ} \text{C}$)

Which one of the following is the mineral for tin?

$A$ and $B$ are two radioactive substances whose half-lives are $1$ and $2$ years respectively. Initially, $10 \, g$ of $A$ and $1 \, g$ of $B$ are taken. The time (approximate) after which they will have the same quantity remaining is ........... $years$.

Degeneration of the corpus luteum causes

Which one of the following statements is correct?

$A$ particle of mass $m$ moves along line $PC$ with velocity $v$ as shown. What is the angular momentum of the particle about $O$?