Elbow joint is an example of

Cry $II$ Ab and Cry $I$ Ab produce toxins that control:

Let $PQ$ and $RS$ be tangents at the extremities of the diameter $PR$ of a circle of radius $r$. If $PS$ and $RQ$ intersect at a point $X$ on the circumference of the circle,then $2r$ equals

The figure shows three long straight wires $P, Q$ and $R$ carrying currents normal to the plane of the paper. All three currents have the same magnitude. Which arrow best shows the direction of the resultant force on the wire $P$?

More than $70\%$ of the world's freshwater is contained in:

Identify the organism shown in the given figure.