Which of the following carbonates undergoes decomposition upon heating?

An object is moving with a uniform acceleration which is parallel to its instantaneous direction of motion. The displacement $(s) - $ velocity $(v)$ graph of this object is

$A$ rod $P$ of length $1 \ m$ is hinged at one end $A$ and there is a ring attached to the other end. Another long rod $Q$ is hinged at $B$ and it passes through the ring. The rod $P$ is rotated about an axis which is perpendicular to the plane in which both the rods are present and the variation between the angles $\theta$ and $\phi$ are plotted as shown. The distance between the hinges $A$ and $B$ is ....... $m$.

Which of the following statements is true?

$A$ point charge $+Q$ is positioned at the centre of the base of a square pyramid as shown. The flux through one of the four identical upper faces of the pyramid is

Which of the following is a buffer solution?