Both Assertion A and Reason R are correct, and R is the correct explanation of A. About 20–25% of CO$_2$ is transported in the blood as carbaminohaemoglobin. The formation of carbaminohaemoglobin is favored by high pCO$_2$ and low pO$_2$, conditions that prevail in the tissues.
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :