The ratio of the longest wavelengths corresponding to the Lyman and Balmer series in the hydrogen spectrum is

What does the given diagram of enzyme action represent?

In the expansion of $(1 + x)^n$,the coefficients of the $p^{th}$ and $(p + 1)^{th}$ terms are respectively $p$ and $q$. Then $p + q = $

In the circuit shown in the figure,the current $I$ is: (in $\,A$)

Consider the following statements $A$ and $B$ and identify the correct answer:
$A$. When a person walks on a rough surface, the direction of the frictional force exerted by the surface on the person is in the direction of his motion.
$B$. When a cycle is in motion, the force of friction exerted by the ground on the front wheel is in the backward direction.

$A$ ring of radius $4a$ is rigidly fixed in a vertical position on a table. $A$ small disc of mass $m$ and radius $a$ is released as shown in the figure. When the disc rolls down,without slipping,to the lowest point of the ring,then its speed will be